Electromagnetic biosensor

ABSTRACT

A system, method, device, and process for making and using an electromagnetic-sensitive biosensor on a biosensor disk to identify and classify an analyte in a sample. The biosensor of the biosensor disk is exposed to a sample containing analytes and a desired analyte adheres to the biosensor. The biosensor is exposed to microspheres that adhere to the analyte. The microspheres cause a detectable change to electromagnetic radiation incident upon the biosensor disk The biosensor disk is rotated during operation and an electromagnetic emitter directs an electromagnetic radiation beam at the biosensor disk. The returned electromagnetic radiation from the biosensor disk is received by a sensor and converted into a signal to indicate the presence of the desired analyte in the sample.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S.application Ser. No. 12/049,012, filed Mar. 14, 2008.

TECHNICAL FIELD

The present invention relates to devices, methods, and processes forusing biologically active compounds and electromagnetic sensors todetect and classify analytes.

BACKGROUND

Biosensor systems are analytic devices that are capable of detectingand, in many cases, estimating the relative concentration of specificsubstances, commonly called analytes, and other parameters of biologicalinterest. The analytes detected can be both inorganic or organic innature. Biosensor systems provide a response that is modulated by thepresence of one or more specific analytes in order to provideinformation to a user that an analyte is present in the system andpossibly an estimate of the concentration of the analyte.

Analytes, when present, are often in very low concentrations, are oftensub-millimeter or smaller in size, and are therefore difficult to detectwithout sensitive equipment designed specifically to detect theirpresence. Often, the substance to be analyzed is exposed to additionalchemicals that attach to the analytes to tag or mark them. With theaddition of the chemical markers, the tagged analytes become muchbigger, respond differently to specific frequencies of incident light,crystallize, or otherwise change physical properties in some way thatmakes them easier to detect. Existing biosensor systems can be expensiveto own and often require advanced technical expertise to operate safelyand effectively. Subsequently, most individuals do not have access to,or sufficient knowledge of, the sophisticated laboratory equipmentnecessary to detect most analytes.

Therefore, when there is a need to have a substance analyzed, labpersonnel or a specialist from, for example, the local forensicsdepartment, will collect a sample and take it back to a laboratory foranalysis. This entails at least three problems. First there is a timelag between when the sample is sent to the laboratory and when resultsare available. Second, there is a sample durability issue wherein theanalyte may change chemically during the time lag between when thesample is taken and when it is analyzed. And third, there is the cost oftransporting the sample and having it analyzed by a laboratory. It wouldoften be advantageous to equip individuals with the ability to detectcertain analytes in situ in real time.

Rotating electromagnetic disks, including optical disks commonly usedfor transferring digital information such as compact disks (CDs) andDigital Video Disks (DVDs), use electromagnetic radiation to readdigital information encoded on the surface of the disk. These rotatingoptical disks provide a convenient means for storing digital informationin a portable device. Electromagnetic sensor disks store informationusing structures that are on the order of a micrometer in scale andpacked closely together on the order of a few micrometers. Devices forreading and interpreting the information stored on rotatingelectromagnetic disks are very common, with many persons having readyaccess to a number of different devices for reading the information.These common devices can resolve the micrometer structures for storingdate and can therefore can also be used resolve tagged analytes ofsimilar scale.

There is a need for a method, device, and process for creating, reading,and evaluating analytes using an electromagnetic sensor disk. Theadditional ability to use some embodiments of the electromagnetic sensordisk with existing electronic devices, including consumer electronics,audio players, and computers for reading the sensed analyte informationprovides additional flexibility and utility.

SUMMARY

Presented is a system and method for using biologically active compoundsand electromagnetic sensors to detect and classify analytes. In anembodiment, a system for detecting an analyte has a biosensor disk withan outer surface and a layer encoded with a data path having staticbaseline data that is capable of being read by electromagneticradiation. A detector chamber along the data path has a surface foraffixing detector ligands. The surface is distinct from the layerencoded with the data path. A detector ligand for binding with theanalyte is affixed to the surface. A detection enhancement means, forexample a microsphere and/or staining agent, that binds to the analytecauses a detectable change to the electromagnetic radiation from a disksystem that accepts the biosensor disk. The disk system accepts androtates the biosensor disk, and has a source of electromagneticradiation that is focused on the layer encoded with the data path and asensor that detects the electromagnetic radiation from the layer encodedwith the data path and converts the electromagnetic radiation into anelectrical signal.

In an embodiment, a system for detecting one or more analytes in asample has a biosensor disk with an outer surface, a layer encoded witha data path having static baseline data that is capable of being read byelectromagnetic radiation, and an interlocking feature for accepting adetector substrate and aligning the substrate with the data path. Adetector substrate has a mating feature for interlocking with thebiosensor disk. A detector ligand affixed to the detector substratebinds with the analyte and a coated microsphere binds with the analyte.The coated microsphere causes a detectable change to the electromagneticradiation. A disk system accepts and rotates the biosensor disk, and hasa source of electromagnetic radiation that is focused on the layerencoded with the data path and a sensor that detects the electromagneticradiation from the layer encoded with the data path and converts theelectromagnetic radiation into an electrical signal.

A method for detecting an analyte in a sample comprises introducing thesample onto a detector substrate of a biosensor disk having a layerencoded with a data path of static baseline data, binding the analyte toa detector ligand on the detector substrate to create a bound detectorligand, introducing a coated microsphere onto the detector substrate,binding the coated microsphere to the bound detector ligand, the coatedmicrosphere creating a detectable change to electromagnetic radiationincident upon the coated microsphere, interconnecting the detectorsubstrate to the detector chamber of the biosensor disk, placing thebiosensor disk in a disk system, rotating the biosensor disk, emittingelectromagnetic radiation and focusing it on the layer encoded with thedata path, receiving a returned electromagnetic radiation from the layerencoded with the data path, and interpreting a change in the returnedelectromagnetic radiation caused by the detectable change to indicatethe presence of the analyte.

The features, functions, and advantages discussed can be achievedindependently in various embodiments of the present invention or may becombined in yet other embodiments further details of which can be seenwith reference to the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures depict multiple embodiments of the device,method, and processes for using an electromagnetic biosensor todetermine and classify analytes. A brief description of each figure isprovided below. Elements with the same reference numbers in each figureindicate identical or functionally similar elements. Additionally, theleft-most digit(s) of a reference number identifies the drawings inwhich the reference number first appears.

FIG. 1A is a view of the top surface of a biosensor disk with adepiction of a continuous spiral data track and an area of detectorchambers.

FIG. 1B is a close-up view of the top surface of a biosensor diskhighlight specific features found in the area of the detector chambers.

FIG. 2 is a view of a disk system that uses electromagnetic radiation toread information encoded on a biosensor disk in the continuous spiraldata track including an area with a detector chamber present.

FIG. 3 a is a cross-sectional view of a biosensor disk of a firstembodiment, wherein the detection chambers are constructed in a sandwichon the surface of an electromagnetic disk with permanently encoded data.

FIG. 3 b is a cross-sectional view of a biosensor disk of a anotherembodiment, wherein the detection chambers are constructed in a sandwichon the surface of an electromagnetic disk with the ability to recorddata.

FIG. 4 is a cross-sectional view of a biosensor disk of a secondembodiment, wherein the detection chambers are constructed on theexposed surface of an electromagnetic disk.

FIG. 5 is a cross-sectional view of a biosensor disk of a thirdembodiment, wherein the detection chambers are constructed as oneunitary element with the data tracks of the biosensor disk.

FIG. 6 is a plan view of a biosensor disk showing an array of pits andlands formed along the continuous data spiral for encoding baselineinformation.

FIG. 7 is a logical block diagram of one embodiment of the system,wherein the results of the biosensor are processed using a computer.

FIG. 8 is a logical block diagram of another embodiment of the system,wherein the results of the biosensor are processed using the human ear.

FIG. 9 is a block diagram depicting the steps necessary to create abiosensor disk of the first embodiment with a single analyte detectorligand.

FIG. 10 is a diagram depicting one embodiment of the detection systemusing micropatterned detector sites and a sectional substrate.

FIG. 11 is a block diagram of one process used to affix a genericdetector ligand to a detector substrate using photoactivatable biotins.

FIG. 12 is a diagram of a first experimental configuration and a graphillustrating an increase in errors during reading of a biosensor diskafter exposure to a drop of solution containing a microspheres.

FIG. 13 is a diagram of a second experimental configuration and a graphillustrating an increase in errors during reading of a biosensor diskafter exposure to a drop of solution containing a microspheres appliedusing a device in contact with the biosensor disk to locally concentratethe microspheres.

FIG. 14 is diagram of a microsphere enhanced detection system thatattaches microspheres to the analytes that are bound to detectorligands.

FIG. 15 is a flowchart of a microsphere enhanced detection methodologyfor attaching microspheres to analytes that are bound to detectorligands.

DETAILED DESCRIPTION

Structure of a Biosensor Disk

FIG. 1 depicts the top surface 140 of a biosensor disk 100. Thebiosensor disk 100 in this embodiment is configured with approximatelythe same dimensions as a compact disc (CD). The biosensor disk 100 canbe configured to a number of different sizes, shapes, andconfigurations, and in this embodiment, the size of a standard audio CDwas selected for convenience only. The biosensor disk 100 has a center101 and a center hole 102 aligned with the center 101. The center hole102 is formed through the main body of the biosensor disk 100 and isroughly cylindrical in shape through the center 101 of the biosensordisk 100. In the case of a biosensor disk 100 adapted to conform with CDstandards, the center hole 102 is approximately 15 mm in diameter.Moving outward from the center hole 102 on the surface of the biosensordisk 100 is the transition area 104. The transition area 104 has adiameter of about 44 mm. The outer surface area of the biosensor disk100 between the transition area 104 to the outer edge 108 is theinformation area 106.

The information area 106 of the biosensor disk 100 has a continuous dataspiral 110. The continuous data spiral 110 extends from the edge of thetransition area 104 and spirals outward toward the outer edge 108. Asingle physical track 112 is defined as one complete turn, 360 degrees,of the continuous data spiral 110 on any arbitrary portion of the dataspiral 110. The track to track separation 114 of a standard CD is 1 μm,while a DVD is measured as 0.7 μm. The track-to-track separation 114 ofthe biosensor disk 100 embodiment shown in FIG. 1A is about 1.6 μm.Other embodiments of the biosensor disk 100 have larger or smallertrack-to-track separation 114 based on a number of factors including thetype of device used to read the biosensor disk 100, the type of analytebeing detected, and the method of creating the detector ligands 380 asdescribed herein.

The biosensor disk 100 of the embodiment shown in FIG. 1A has a discreteanalyte detector region 120. The analyte detector region 120 extendsroughly from the inner diameter of the information area 106 to the outeredge 108, covering approximately the same radial position on the surfaceof the biosensor disk 100. In one embodiment, the detector region 120 isroughly rectangular in shape with parallel sides. In an alternateembodiment, the detector region 120 is more of a pie shape and has sidesthat diverge the further they are displaced from the center 101, forexample the sides can be portions of a radius of the biosensor disk 100.

A small portion of the analyte detector region 120 is shown in detail inFIG. 1B. The analyte detector region 120 is comprised of multiple typesof detector chambers 130 a, 130 b, 130 c, and collectively 130. Thedetector chambers 130 are displaced on the biosensor disk 100 relativeto the continuous data spiral 110 and specifically the individualphysical tracks 112. The detector chambers 130 are configured such thatthey overlap either partially or completely the track of at least onephysical track 112, as in the case of the hexagonal detector chamber 130a and the circular detector chamber 130 b. Other detector chambers 130are configured to substantially overlap more than one physical tracks112. In some embodiments, described in detail later, the detectorchambers 130 are at the same depth in the biosensor disk 100 as thephysical track 112. In other embodiments, the detector chambers 130 arelocated between the physical track 112 and the top surface 140 of thebiosensor disk 100. In still other embodiments, the detector chambers130 are located on the top surface 140 of the biosensor disk 100 or on aseparate element that is integrated onto the biosensor disk 100.

In an alternate embodiment, the detector chambers 130 are replaced withone or more binding sites that reside on the analyte detector region120. In an alternate embodiment, the analyte detector region 120 ispressed into a corresponding groove in the biosensor disk 100.

Disk System

A schematic of one embodiment of a disk read/write system, or moregenerally a disk system 200 is shown in FIG. 2. The disk system 200 iscomprised of a disk rotation system 266, and a radiation emitter anddetection system 268. The disk system 200 is integrated together with abiosensor disk 100 to create the biosensor system 210. The disk system200 is comprised of multiple components to rotate the biosensor disk100, generate electromagnetic radiation, focus the electromagneticradiation approximately on the top surface 140 of the biosensor disk100, receive reflected radiation, and interpret and process thereflected radiation to generate useable signals. The term “reflectedradiation”, used hereafter for convenience, should be interpretedbroadly to comprise the returned radiation resulting from the incidenceof electromagnetic radiation on the biosensor disk 100 as would beunderstood by those of skill in the art. Detectable changes to thereturned radiation include, but are not limited to, changes due toabsorption, reflection, dispersion, transmission, refraction, anddiffraction of the electromagnetic radiation by the biosensor disk 100.

The disk system 200 has a radiation emitter 202 that produces sourceradiation 204 within a specific wavelength range. The radiation emitter202 in some embodiments produces source radiation 204 at a relativelyconstant power or intensity level. In other embodiments, the radiationemitter 202 produces source radiation 204 at two or more power levels.In the case of one embodiment of the disk system 200 adapted for CDmedia, the radiation emitter 202 is a solid state laser or lightemitting diode (LED) generating light between about 760 nm and 790 nm.In the case of an embodiment of the disk system 200 adapted for DVDmedia, the radiation emitter 202 is a solid state laser or lightemitting diode (LED) generating light between about 640 nm to 660 nm orabout 400 nm to about 410 nm. Alternative radiation emitters 202 can beused based on the selective physical characteristics of the biosensordisk 100 including reflectivity and the composition of the continuousdata spiral 110, the detector chambers 130, detector ligands 380, andother parameters known to those of skill in the art.

The next element of the disk system 200 is the collimator lens 206. Thecollimator lens 206 is adapted to collimate the incoming sourceradiation 204, such that the output is collimated radiation 208 withparallel waves and a plane wavefront. In the embodiment shown, thecollimator lens 206 is a parabolic concave lens with the radiationsource 202 at the focus of the mirror. Other methods of collimating thesource radiation 204 into collimated radiation 208 can be used as knownto those of ordinary skill in the art.

The embodiment shown in FIG. 2 also includes a diffraction grating 212.The diffraction grating 212 effectively splits the collimated radiation208 into a single main central peak and two secondary peaks on each sideof the main central peak. The diffraction grating 212 is not present inother embodiments of the disk system 200.

The next element in this embodiment of the disk system 200 shown in FIG.2 is the polarizing prism 214. The polarizing prism 214 polarizes theincoming collimated radiation 208 and emits linearly polarizedcollimated radiation 216 toward the quarter wave plate 218. Thepolarizing prism 214 in this embodiment enables the incoming collimatedradiation 208 to be emitted toward the biosensor disk 100, whileenabling the reflected radiation 224 to be directed toward the radiationdetector 240. The separation of the incoming collimated radiation 208from the reflected radiation 224 is achieved in the polarizing prism 214of this embodiment of the disk system 200 and is constructed from twoprisms of birefringent material, that direct the light unequally indifferent direction bonded together (bond line not shown) along adiagonal to direct the radiation. The planar physical arrangement of theradiation emitter 202 and the radiation detector 240 is a matter ofconvenience and is selected in this case due to the ability to create arelatively flat structure and minimize the total depth of the disksystem 200. In another embodiment of the disk system 200, the radiationemitter 202 and the radiation detector 240 have separate radiation pathsand they are co-located over the surface of the biosensor disk 100. Instill another embodiment of the disk system 200, the radiation emitter202 faces one surface of the biosensor disk 100 while a collecting lensis mounted facing the opposite surface of the biosensor disk 100 tocollect radiation passing through the biosensor disk 100.

In the embodiment of the disk system 200 shown in FIG. 2, the quarterwave plate 218 takes the linearly polarized collimated radiation 216 andemits circularly polarized radiation 219. The quarter wave plate 218 isoriented such that the optical axis of the quarter wave plate 218 isoffset by 45 degrees from incidence of the linearly polarized collimatedradiation 216.

The circularly polarized radiation 219 is directed toward a focusinglens 221. Output focused radiation 222 from the focusing lens 221 shineson the top surface 140 of the biosensor disk 100. The material thatforms the top surface 140 of the biosensor disk 100 further focuses thefocused circularly polarized radiation 222 onto a spot 250 on a specificphysical track 112. The spot 250 is approximately circular or oval inshape and approximates the shape of the intersection of a cone by aplane perpendicular to the cone's axis. In one embodiment of the disksystem 200 adapted for CD media, the diameter of the spot 250 at thelevel of the physical track 112 is about 2.1 μm. In another embodimentof the disk system 200 adapted for DVD media, the diameter of the spot250 at the level of the physical track 112 is about 1.3 μm or 0.6 μm. Inyet other embodiments of the disk system 200, the diameter of the spot250 of focused radiation 222 at the level inside the biosensor disk 100is selected to maximize the signal from the detector chamber 130.

The vertical distance between the lens 221 and the top surface 140 ofthe biosensor disk 100 is controlled by a lens positioner 220. The lenspositioner 220 in the embodiment of the disk system 200, shown in FIG.2, focuses the focused radiation 222. In this embodiment of the disksystem 200, the lens positioner 220 changes the focus point by as muchas 0.5 mm during operation. The positioning drive moves the lens 221 upand down vertically in response to errors detected at the detector 240due to changes in the circularity of the beam at the detector 240 whenthe focused radiation 222 is improperly focused due to the circularnature of the lens 221. In other embodiments of the disk system 200, thelens 221 remains substantially fixed relative to the top surface 140 ofthe biosensor disk 100. In yet another embodiment of the disk system220, the position of the lens 221 relative to the top surface 140 of thebiosensor disk 100 is actively controlled to maximize the spot 250 sizerelative to the detector chambers 130 and physical track 112 passingunder the point where the focused radiation 222 is focused.

The surface (not explicitly shown in the embodiment depicted FIG. 2) ofthe physical track 112 in the embodiment shown is a reflective surface340, as illustrated on FIGS. 3 a, 3 b. The reflective surface 340 causesthe incident focused radiation 222 on the spot 250 to be substantiallyreflected back as reflected radiation 224 toward the lens 221. Thereflected radiation 224 passes through the lens 221. In the embodimentshown, the lens 221 is a circular lens adapted such that as the lens 221is out of focus with the physical track 112, the circularity of thereflected radiation 224 is distorted into an oval shaped beam that isdetected at the radiation detector 240 to provide a feedback signal tothe lens positioner 220. After passing through the lens 221, thereflected radiation 224 passed in through the quarter wave plate 218 inthe opposite direction from the linearly polarized collimated radiation216. The reflected radiation 224 after passing through the quarter waveplate 218 is then linearly polarized at 90 degrees and passed throughthe polarizing prism 214 to be directed as polarized reflected radiation226 directed toward a detector lens 228. The detector lens 228 createsfocused reflected radiation 230 that is directed toward the radiationdetector 240. The focused reflected radiation 230 falls on the radiationdetector 240 as a reflected spot 252 that is correlated to the reflectedradiation 224 from the spot 250. An alternative embodiment of the disksystem 200 eliminates the detector lens 228 and instead directlyreceives the polarized reflected radiation 226 on the radiation detector240.

The radiation detector 240 in the embodiment shown in FIG. 2 iscomprised of four separate radiation detectors 242, 244, 246, and 248.The four detectors are arranged in a square matrix with an upper leftdetector 242, an upper right detector 244, a lower left detector 248 anda lower right detector 246. The radiation detector 240 converts theincident radiation falling on itself into a signal, most commonly ananalog electronic signal corresponding to the amount of reflectedradiation falling on the reflected spot 252. The differential signalsfrom the separate detectors provide feedback for tracking both thedistance of the lens 221 over the top surface 140 of the biosensor disk100 as well as the radial track position 270 of the lens 221 relative tothe physical track 112 of the continuous data spiral 110. The radialtrack position 270 provides a means for indicating which physical track112 of the biosensor disk 100 that the spot 250 is focused on. The lens221 is properly focused on the physical track 112 at the proper distancefrom the top surface 140 when the output of all the detectors 242, 244,246, and 248 is substantially the same after steady state offsets areremoved from the signal. Differences in the output of the differentdetectors 242, 244, 246, and 248 provide an estimate of whether or notthe lens 221 is tracking the proper radial track position 270 or theproper position of the lens 221 relative the surface of the biosensordisk 100. In another embodiment, the radiation detector 240 is a singledetector that does not provide differential output. In still otherembodiments, the radiation detector 240 is a multi-element radiationdetector with more than four detector elements, including a chargedcoupled device (CCD) or complimentary metal oxide sensor (CMOS) or otherimaging detector with greater numbers of radiation detector elementsthat provide a greater resolution estimate of the overall position,shape or geometry of the reflected spot 252 and strength of thereflected spot 252.

The lens 221 moves along a radial track 270 in order to track thefocused radiation 222 on the top surface 140 of the biosensor disk 100along the continuous data spiral 110. The movement of the lens 221 alongthe radial track 270 is accomplished by a linear motion carriage coupledwith rotary electric motor, not shown in FIG. 2. The rotation of theelectric motor causes the linear motion carriage to move back and forthalong the radial track 270, thereby allowing the lens 221 to focus on aspecific portion, or physical track 112 of the continuous data track110. In one embodiment of the disk system 200, the entire radiationemitter and detection system 268 moves on the same linear motioncarriage as the lens 221. In yet another embodiment, the linear motioncarriage is a direct drive linear electric motor. Other mechanisms andmeans of moving the lens 221 or the entire radiation emitter anddetection system 268 along the radial data path 270 are available to oneof ordinary skill in the art.

The biosensor disk 100 is spun by a disk rotation system 266 comprisinga rotary motor 260, with a shaft 262 and a hub 264. The center hole 102of the biosensor disk 100 is adapted to mate with the hub 264. When thecenter hole 102 is mounted on the hub 264 the amount of rotationalslipping between the biosensor disk 100 and the hub 264 is minimized.The rotation of the shaft 262 in the direction A by the rotary motor 260thus rotates the hub 242 in the direction A and urges the biosensor disk100 to rotate in response, also in the direction A. The rotationalvelocity of the rotary motor 260 is controlled by the input signal tothe motor. In the embodiment shown in FIG. 2, the rotational velocity ofthe rotary motor 260 remains constant. In other embodiments, therotational velocity of the rotary motor 260 is controlled to maintain aconstant linear velocity of the physical track 112 over the lens 221. Instill other embodiments, the rotary motor 260 changes velocity based onthe quality of information being read and the amount of errors beinggenerated at the radiation detector 240. The combination of the rotationof the biosensor disk 100 and the movement of the lens 221 enables thefocused radiation 222 to be directed at and the reflected radiation 224received from the biosensor disk 100 from substantially any point alongthe continuous data spiral 110 encoded on the biosensor disk 100. Thedisk system 200 is thus capable of reading data from across the entirecontinuous data spiral 110 of the biosensor disk 100.

Non-Prismatic Disk System

Another embodiment of the disk system 200, not shown, eliminates thepolarizing prism 214 from the configuration of the entire radiationemitter and detection system 268. Instead the radiation emitter 202 andassociated lens and filters are focused directly on the surface of thebiosensor disk 100, typically at an angle. A second lens (not shown)receives the reflected radiation and focuses it on a radiation detector240. The non-prismatic disk system eliminates some of the need forfiltering and polarizing the radiation for reading the biosensor disk100, thereby reducing the number of components in the optical path andpotentially increasing the overall energy transferred from the radiationemitter 202 to the spot 250.

Linear Disk System

In another embodiment, the disk system 200 eliminates the polarizingprism 214 from the configuration of the entire radiation emitter anddetection system 268. In this another embodiment, the radiation emitter202 focuses on the top surface 140 of the biosensor disk 100. Thebiosensor disk 100 is substantially transparent to the radiationdirected to impinge on a specific spot 250 on the physical track 112,thereby allowing the radiation to pass through the other components ofthe biosensor disk 100 and be received by the radiation detector 240 asit emerges from the opposite side of the biosensor disk 100.

Continuous Data Spiral of Pits and Lands

Two separate embodiments of the continuous data spiral 110 are shown inFIG. 3. The first embodiment, in FIG. 3 a, is an example of a continuousdata spiral 110 formed as an array of pits and lands 330 formed in thesubstrate 310, also shown in plan view in FIG. 6. The array of pits andlands 330 are coated with a reflective surface 340 such that when thefocused radiation 222 at the spot 250, the focused radiation 222 issubstantially reflected from the reflective surface 340 as reflectedradiation 224. The reflective surface 340 is selected by one or ordinaryskill in the art to achieve the necessary reflection of the focusedradiation 222 necessary for the radiation detector 240 to detect thechange in the radiation due to the structures encoded on the continuousdata spiral 110. In the case of the embodiments of the disk system 200that utilize CD and DVD wavelength radiation, the reflective surface 340is commonly constructed of silver, aluminum, gold or copper.

For the embodiment of the disk system 200 with a polarizing prism 214,the depth of the pit 302 is nominally the quarter wave distance of thefocused radiation 222. The depth of the pit 302 causes destructiveinterference with the reflected radiation 224, thus reducing the overallintensity of the reflected radiation 224. The reduction in intensity ofthe reflected radiation 224 causes the radiation detector 240 to read anaverage decease in radiation at the reflected spot 252 that allows thedisk system 200 to differentiate between a pit 302 and the lands 304.

As shown in FIG. 6, the pits 302 are substantially ellipticaldepressions formed in the surface of the substrate 310. The major axisof each elliptical depression, pit 302, is oriented along the physicaltrack 112. Between each pit 302, both along the physical track 112 andbetween the physical track 112 are considered to be lands 304. Thedifference in height between pits 302 and lands 304 cause the intensityof the reflected radiation 224 to vary based on whether the focusedradiation 222 falling on a specific spot 250 is reflected as higher orlower intensity reflected radiation 224. The difference in intensity ofthe radiation provides a means for the disk system 200 to determinewhether the spot 250 is falling on a pit 302 or a land 304 area of thebiosensor disk 100.

For the embodiment of the disk system 200 with a non-prismatic radiationsource and sensor, the difference in depth between a pit 302 and a land304 causes the reflected radiation 224 to fall on a different portion ofthe radiation detector 240 due to the difference in distance between thepoint of reflection, defined by the spot 250 falling on the reflectedsurface 340 in the area of a pit 302 versus a land 304. For the lineardisk system 200, the signal difference in depth between a pit 302 or aland 304 is achieved through the relative transmissivity of thesubstrate 310 material to the focused radiation 222. In an alternativeembodiment, the reflective surface 340 is replaced by a substantiallynon-reflective and non-transmissive material. This reflective surface340 is then patterned using multiple techniques including, but notlimited to scribing, laser ablation, photolithography, and othertechniques necessary to create voids in the non-reflective andnon-transmissive material located where the reflective surface 340 isnominally placed in order to create detectable high and low points forthe radiation detector.

The embodiment of the biosensor disk 100 shown in FIG. 3, has aprotective substrate 312 covering over the reflective material 340 onthe backside 342 of the biosensor disk 100 to protect the reflectivematerial 340 from accidental damage.

Substrate Materials And Fabrication

In the embodiment of the permanently formed continuous data spiral 110shown in FIG. 3 a and in FIG. 6, the pits 302 and lands 304 are formedwhen the biosensor disk 100 is initially fabricated, typically bypressing or casting of the substrate 310. The substrate 310 in the caseof the permanently formed continuous data spiral 110 is comprised of aseries of depressions or pits 302 surrounded by the other surface of theface of the substrate 310, commonly called lands 304. A top view ofthree physical tracks 112 of a continuous data spiral 110 withpermanently recorded information in the form of an array 330 of pits 302and lands 304 is shown in FIG. 6. The substrate 310 of the embodiment ofthe biosensor disk 100 shown in FIG. 6 is typically a polycarbonatematerial.

Other substrate materials can be used for the biosensor disk 100including other polymer materials or other metallic and non-metallicmaterials. In one embodiment, the substrate 310 of the biosensor disk100 is formed from polystyrene. In another embodiment of the biosensordisk 100, the polycarbonate material is replaced by a single-crystalsilicon. The single crystal silicon enables the pits to be formed usingcommon microelectronic and micro fabrication techniques, providing ahigh degree of accuracy and repeatability from biosensor disk 100 tobiosensor disk 100. In still other embodiments, the single crystalsilicon is replaced by other substrate materials, including but notlimited to gallium arsenide, silicon carbide, silicon-on-insulator(SOI), and silicon nitride. For example, a polycarbonate biosensor disk100 has a refractive index of approximately 1.55. A substrate 310comprised of SiO2 normally has a refractive index of 1.45, meaning thatthere would be a difference in reflectivity between the substrate 310and the biosensor disk 100 if not corrected. By doping the SiO2 of thesubstrate 310 with approximately 3% Nitrogen, the substrate 310 can beengineered to have a refractive index of 1.55, which is approximatelythe same as the refractive index of the biosensor disk 100. All of thesematerials can be processed using common microelectronic fabricationtechniques using techniques such as photolithography, sputtering,chemical vapor deposition, deep reactive ion etching, wet and dryetching, and other wafer fabrication techniques, as would be generallyunderstood by one of ordinary skill in the art, to create a combinationof detector chambers 130 and pits 302 and lands 304 necessary to encodethe baseline data 902.

In another embodiment, the biosensor disk 100 has a polycarbonateportion and a silicon crystal potion. In this embodiment, the majorityof the biosensor disk 100 is made of polycarbonate while the analytedetector region 120 is made of a higher melting point material, such asSiO2 (silicone dioxide). This has the advantage of allowing the majorityof the disk to be produced inexpensively, while allowing the analytedetector region 120 to be constructed of a more durable material thatcan withstand high temperature processes such as those commonly used inmicroelectronic fabrication as described above.

The selection of specific substrate materials is guided by a number offactors, including compatibility with the desired analytes, physicalstrength, the ability to create alternative shapes, the type ofradiation necessary to discriminate between detector ligands 380 andbound detector ligands 480 that are affixed to an analyte 960. Otherfactors that impact the selection of materials include materialscompatibility between different elements of the physical structure andthe ability to create the continuous data spiral 110 in the material atthe resolutions necessary to accommodate the desired detector chambers130.

The embodiment shown in FIG. 6 is configured with pits 302 and lands 304sized for an unmodified CD reader. In this embodiment, each of the pits302 has a pit width 6A of approximately 0.5 μm. The major axis of eachpit 302 is oriented along the physical track 112. The pit length 6C isbased on the information encoded in the substrate at that specificlocation (see description below) and ranges from about 278 nm to about3560 nm. The spaces outside of the pits 302 are called land 304.

Continuous Data Spiral Formed from Writeable Materials

The second embodiment of recoding the baseline information or baselinedata 902 on the continuous data spiral 110 is shown in FIG. 3 b. Thissecond embodiment uses writeable materials that enable the baseline data902 to be written to the biosensor disk 100 after the biosensor disk 100has been fabricated. The biosensor disk 100 is formed with a continuouspregroove 308 along the continuous data spiral 110. The continuouspregroove 308 is formed in the substrate 310 using the similartechniques as used for forming the pits 302 and lands 304 of FIG. 3 a.The continuous pregroove 308 in the embodiment shown is a groove with awidth of 0.6 μm. The continuous pregroove 308 has a radial wobble itspath with at 22.05 kHz. The wobble is frequency modulated with a 1 kHztime code that provides an Absolute Time In Pregroove (ATIP). The radialwobble and the ATIP frequency modulate provide additional informationthat the radiation detector 240 can use to control the position of thespot 250 on the surface of the biosensor disk 100.

The continuous pre-groove is coated in this embodiment with a writeablematerial 314. The writeable material 314 in the embodiment in FIG. 3 bis an ablative material that absorbs focused radiation 222 directed atthe writeable material 314. When the radiation emitter 202 is emittingradiation in a high power mode, the writeable material 314 is heated upand upon cooling incurs a local phase change from one phase, typicallyan amorphous phase as deposited on the substrate 310, to a second phasetypically polycrystalline in form. The transmissivity of the writeablematerial 314 to the focused radiation 222 changes from the amorphousstate to the crystalline state of the writeable material 314. Thewriteable material 314 is coated with a reflective layer 340 thatreflected the focused radiation 222 back. The change in the amorphousstate of the writeable material 314 thus modulates the light passingthrough the writeable layer 314. The use of heat from radiation tochange the phase of the materials used in the writeable layer 314enables the writeable layer 314 to be written with information after thebiosensor disk 100 is manufactured. This flexibility enables thebiosensor disk 100 to have the baseline data 902 encoded in thecontinuous data spiral 110 adapted for the detection of specific ligandsbased on the type of detector chambers 130 being used.

In alternative embodiments, the writeable material 314 is a phase changematerial that can be reversed such that the portion of the writeablematerial 314 under the spot 250 can be selectively changed between twodifferent phases with two different transmissivity levels for bothencoding information and clearing information from the continuous dataspiral 110. The writeable material 314 used in a linear disk system 200can be used without a reflective surface 340.

There are a number of different writeable materials 314 and reflectivematerials 340 that can be used to create the writeable layer. In theembodiments suitable for encoding the baseline data 902 for a CD or DVDthere are multiple materials used for the writeable layer, including butnot limited to the following writeable materials 314: Cyanine,Pthalocyanine, Azo, and Formazan. Other combinations are known to thoseor ordinary skill in the art, and other combinations can be used thatare adapted to the use of different wavelengths of radiation.

Protected Detection Chamber Above Continuous Data Track

The embodiment of the biosensor disk 300 with protected detectorchambers 130 shown in FIGS. 3 a and 3 b has a detector substrate 350placed above and integrated with the substrate 310. The biosensor disk300 with protected detector chambers 130 shown in FIGS. 3 a and 3 b isshown as an exploded assembly for easy viewing. The individual elementsin the assembled biosensor disk 300 with protected detector chambers 130physically abut each other when they are assembled in the direction 3A.The detector substrate 350 has detector chambers 130 formed in thedetector substrate 350. The detector chambers 130 are formed in thedetector substrate 350 using a multitude of processes known to those ofordinary skill in the art, including the casting or pressing processused to form the pits 302 and lands 304 in the substrate 310. Thedetector substrate 350 is fabricated from a variety of differentmaterials, ranging from polymers such as polycarbonate and non-metallicmaterials like silicon through metallic materials. The selection of thedetector substrate 350 by one of ordinary skill in the art is based on anumber of factors, including but not limited to, the relative materialsmatch between the substrate 310 and the detector substrate 350, theability to glue or otherwise join the substrate 310 to the detectorsubstrate 350 in those applications that require a single elementsystem, the relative transmissivity of the material relative to thefocused radiation 222, and other factors including the ability of thedetector substrate 350 to bind to detector ligands 380, thereby formingbound detector ligands 480, and being substantially unreactive to theanalyte 960 and or other materials present in the sample 950.

The detector chambers 130 formed in the detector substrate 350 areadapted to maximize the change in the reflected radiation 224 detectedat the radiation detector 240 relative to the baseline data 902 encodedon the substrate 310. The detector ligands 380 are placed in thedetector chamber 130 of the detector substrate 350. The detector ligands380 are adapted to bind, accept, or otherwise capture specific analytes960 found in the sample 950 to be analyzed. When the detector ligands380 bind to the analyte 960, they form bound detector ligands 480. Thebound detector ligands 480 have a lower radiation transmissivityproperties as compared to the detector ligands 380, thereby changing thesignal received by the disk system 200. The process for attaching thedetector ligands 380 to a substrates and the selection of detectorligands 380 that will form bound detector ligands 480 with specificanalytes 960, is described in greater detail below.

In this embodiment, an elongated channel or fluidic passage 360 is alsoformed in the substrate (shown as hidden lines). The fluidic passage 360enables a sample 950 to be analyzed to be inserted at the entrance tothe fluidic passage 360 and then travel along the fluidic passage 360 tothe detector chamber 130 in order to be exposed to the detector ligands380. In one embodiment, the fluidic passage 360 is formed between thedetector substrate 350 and the reflective surface 340. In anotherembodiment, the fluidic passage 360 is formed fully inside the detectorsubstrate 350 by either integrating multiple detector substrates 350together or by burrowing a channel directly through the detectorsubstrate 350. Additional fluidic control elements, as described below,are integrated within the fluidic passage 360 and detector chamber 130areas in other embodiments to control the flow of the sample 950 throughthe biosensor disk 300.

In the embodiment depicted in FIGS. 3 a and 3 b, the detector substrate360 is bound to the substrate during the fabrication process of thebiosensor disk 300 with protected detector chambers 130. This creates asealed system, whereby the detector ligands 380 are protected by thesubstrate 310 and the detector substrate 350. Prior to use, if thebaseline data 902 has not been encoded on the continuous data spiral110, the biosensor disk 300 with detector ligands 380 can be encodedimmediately prior to use after the detector substrate 350 has beenaffixed to the substrate 310. Alternatively, for biosensors disks 300with pre-encoded continuous data spirals 110 and for writeable biosensordisks 300 with the writeable material 314 on the substrate 310, thesedisks are pre-encoded with baseline data 902 adapted to maximize thechanges recorded by the radiation detector 240 and interpreted by theinterpreter.

The sample 950 and the analyte 960 are placed into the embodiment of thebiosensor disk 300 with the detector substrate 350 affixed to thesubstrate 310. The sample 950 with the analyte 960 contained within,flow through the fluidic passages 360 to the detector chamber 130. In analternative embodiment, the detector substrate 350 is separate from thesubstrate 310. In one embodiment, the detector substrate 350 is emersedas a single unit into one or more substances, including being placed inpreparatory fluids prior to being exposed to the sample 950. Thedetector substrate 350 is then processed in order to maximize theadhesion of the analyte 960 to the detector ligands 380. Afterprocessing of the detector substrate 350 separately from the substrate310, the detector substrate 350 is affixed or joined to the substrate310. In one embodiment, the detector substrate 350 fits into physicalmating structures that help orient and lock the detector substrate 350in radial relation to the substrate 310. These physical matingstructures can include, but are not limited to, tongue and grooves, slotand tabs, spoke and channel structures, and other unique geometriescapable of orienting the detector substrate 350 relative to thesubstrate 310. In yet another embodiment, the detector substrate 350 isaffixed to the substrate 310 with an adhesive compound placed betweenthe detector substrate 350 and the substrate 310. The adhesive compoundcould be used independently or in conjunction with one of the physicalmating structures described above. In still another embodiment, thedetector substrate 350 is held against the substrate 310 using anexternal clamping structure, such as a clamping ring.

Exposed Detection Chamber Above Continuous Data Track

FIG. 4 depicts an alternative embodiment that places the detectorchamber 130 on the exposed top surface 140 of the biosensor disk 400with exposed detector chambers 130. The biosensor disk 400 with exposeddetection chambers 130 shown in FIG. 4 is shown as an exploded assemblyfor easy viewing. The individual elements in the assembled biosensordisk 400 with exposed detection chambers 130 physically abut each otherwhen they are assembled in the direction 4A.

The detector substrate 350 for the biosensor disk 400 with exposeddetector chambers 130 is fabricated using the same fundamentalfabrication and materials approaches discussed in the fabrication of thebiosensor disk 300 with protected detector chambers 130 above. Detectorligands 380 are similarly attached to detector chambers 130. The exposeddetector substrate 350 is affixed to the substrate 310, in this caseshown with a continuous pregroove 308 and writeable material 314 inaddition to the reflective layer 340 and protective substrate 312,either prior to or after exposure to the sample 950. The detectorsubstrate 350 is affixed to the substrate 310 using the similartechniques as well.

Integrated Detection Chamber Formed with Continuous Data Track

FIG. 5 depicts an alternative embodiment that integrates the detectorchamber 130 on the substrate 310 with the continuous data spiral 110 tocreate a biosensor disk 500 with integrated detection chambers 130. Thebiosensor disk 500 with integrated detector chambers 130 shown in FIG. 5is shown as an exploded assembly for easy viewing. The individualelements in the assembled biosensor disk 500 with exposed detectionchambers 130 physically abut each other when they are assembled in thedirection 5A.

The biosensor disk 500 with integrated detector chambers 130 places thedetector chambers 130 on the same plane as the pits 302 and lands 304 orcontinuous pregroove 308 and fabricates the physical structure of thedetector chambers 130 as part of the same fabrication process. Thebiosensor disk 500 with integrated detector chambers 130 shown in FIG. 5includes both a continuous data spiral 110 comprised of pits 302 andlands 304 and a continuous data spiral 110 formed with a continuouspregroove 308 and writeable material 314.

The detector chambers 130 on the biosensor disk 500 are sized andadapted to appear to the disk system 200 as the equivalent to a pit 302in the surface of the substrate 310. The detector ligands 380 areattached to the detector chambers 130 using the processes outlinedbelow. The detector chambers 130 are in one embodiment separatelycovered by a thin film protective coating (not shown) to separate thedetector chamber from the reflective layer 340 or the writeable material314. In another embodiment, the detector chambers 130 are integratedwith and exposed to the writeable material 314 or the reflectivematerial 340. The substrate 310 is affixed to the reflective layer 340or writeable material 314 and reflective layer 340 using either thermalbonding or adhesive means based on the ability of the detector ligands380 to withstand a given process.

Microfluidic Handling

The embodiment shown in FIG. 5 depicts a variety of differentmicrofluidic handling approaches for enabling the transport of thesample 950 to a given detector chamber 130 whereby an analyte 960 canbind with the detector ligands 380 to change the relative transmissivityof the detector chamber 130 and highlight the presence of the analyte960 in the sample 950. The microfluidic handling approaches depictedherein are appropriate for all embodiments of the biosensor disk 100,300, 400, 500. They are highlighted on the biosensor disk 500 withintegrated detector chambers 130 for convenience only.

A detector chamber 130 is fed from an input hub chamber 504. The inputhub chamber 504 occupies the central portion of the biosensor disk 500.A means is provided for a sample 950 to be input into the input hubchamber 504. The input hub chamber 504, in one embodiment, has aflexible bung enabling a syringe or other object to be pressed into theinput hub chamber 504 for injecting the sample 950. In anotherembodiment, the input hub chamber 504 has a resealable lid or cover (notshown) that enables the input hub chamber 504 to be exposed and filled.Other means and methods of inputting a fluid into the input hub chamber504 for distribution to the remainder of a given biosensor disk 500 areavailable to those of ordinary skill in the art. In the embodiment shownin FIG. 5, the biosensor disk 500 with integrated detector chambers 130has one type of fluidic passage 360, in this case, an input hub todetector chamber connector 502 connecting the input hub chamber 504 to adetector chamber 130.

A second method of inputting the sample 950 into a detector chamber 130is through a another type of fluidic passage 360, a top surface inputpassage 506. The top surface input passage 506 provides a means foraccessing a detector chamber 130 through the substrate 310. The topsurface input passage 506 in one embodiment is covered with a bung orsimilar flexible material that can be pierced by a sharp object orneedle thereby allowing the sample 950 to flow into the top surfaceinput passage 506 and the detector chamber 130. In one embodiment, thevolume formed within the top surface input passage 506 and the detectorchamber 130 is held at a vacuum, such that when the bung is pierced by aneedle or other instrument, the sample 950 is urged into the top surfaceinput passage 506 and the detector chamber 130.

Two microfluidic passages 360 can be combined to enable a flow ofsubstances from the input fluidic passage 360 through the detectorchamber 130 to an outlet fluidic passage 360. For example, in anotherembodiment, two top surface input passages 506 (only one shown forconvenience) are combined such that fluid is inserted into one topsurface input passage 506 while the air presently tapped within thevolume formed by the detector chamber 130 and the top surface inputpassages 506 is displaced through the second top surface input passage506. In yet another embodiment, the volume formed within the top surfaceinput passage 506 and the detector chamber 130 is filled with an inertgas or fluid, such as nitrogen, argon, or distilled water, or siliconeoil, selected to minimize adverse effects to the detector ligands 380inside the detector chamber 130. A pair of top surface input passages506 are used together with one top surface input passage 506 being usedto input the sample 950 while the other top surface input passage 506 isused to exhaust the inert gas or fluid. Multiple combinations of fluidicpassages 360 can be used by one of ordinary skill in the art toencourage the flow of the sample 950 through the detector chambers 130and also in some embodiments provide an additional means of protectingthe detector ligands 380 prior to use.

Yet another method of inputting a sample 950 into a detector chamber 130is through yet another type of fluidic passage 360, a bottom surfaceinput passage 508. The bottom surface input passage 508 passes throughthe protective substrate 312 and the reflective surface 340 and ifpresent any other layers between the protective substrate 312 and thedetector chamber 130, including a writeable material 314. The bottomsurface input passage 508 operates in a similar manner and is configuredin similar ways to other fluidic passages 360. Similarly to the otherfluidic passages 360, the bottom surface input passage 508 in someembodiments is lined to isolate the sample 950 from the materialssurrounding the fluidic passage 360.

Another method of transporting the sample 950 through a biosensor disk100, and particular in the case of the biosensor disk 500 withintegrated detector chambers 130 shown in FIG. 5 is yet another type offluidic passage, an interchamber fluidic passage 510. The interchamberfluidic passage 510 enables a sample 950 and other fluids or gasespresent in a given volume defined by the detector chambers 130 and thefluidic passages 360 to pass from one detector chamber 130 anotherdetector chamber 130.

The embodiment of the biosensor disk 500 with integrated detectorchamber 130 shown in FIG. 5 has yet another type of fluidic passage 360,an edge exhaust passage 512. The edge exhaust passage 512 enables therelease of fluids and/or gasses inside the volume of the fluidicpassages 360 and the detector chambers 130 and allows their release tothe outer edge 108 of the biosensor disk 100, or the biosensor disk 500with integrated detector chambers 130, as shown in embodiment in FIG. 5.

Controlled Fluidic Mixing and Fluid Flow

In still other embodiments, the microfluidic passages 360 and thedetector chambers 130 are combined with other microfluidic structuresand control elements for maximizing the binding of the detector ligands380 to the analyte 960 to form bound detector ligands 480 adapted fordetection by the disk system 200. These elements include filtrationblocks 540, removable barriers 530, passive heaters 520, electrophoreticelements 560, active heaters 522, and additional sensors 524.

In the embodiment shown in FIG. 5, there is a passive heater 520 placedalong the underside of a detection chamber 130. The passive heater 520is adapted to absorb the focused radiation 222 from the disk system 200and convert the absorbed radiation to heat. The passive heater 520 isarranged in a pattern around the detector chamber 130 and relative tothe continuous data spiral 110 and its baseline data 902 such that theabsorbed radiation is treated as information. The disk system 200 iscommanded to read the track over the passive heater 520 a number oftimes based on the absorbativity of the passive heater 520, the amountof heating desired in the detector chamber 130, and other factors inorder to heat the detector chamber 130 in the vicinity of the passiveheater 520. This localized heating provides a means for encouraging thebinding of the analyte 960 to the detector ligands 380 or in alternativeprocesses for encouraging mixing and chemical reactions between thesample 950 and chemicals located within the detector chamber 130. Inalternative embodiments, the passive heater 520 is placed in proximityto fluidic passages 360 to heat the sample 950 in the vicinity of thepassive heater 520.

A filtration block 540 is placed within a fluidic passage 360, in theembodiment shown in FIG. 5, the top surface input passage 502. Thefiltration block 540 is formed of materials suitable for filtering thesample 950 prior to, or between exposure to different detector chambers130 in the biosensor disk 500. A person of ordinary skill in the artwill select appropriate filtration materials, including the use ofmultiple filtration blocks 540 in a cascade manner, to filter andprepare a given sample 950 prior to entering a detector chamber 130.Some materials used for the filtration block 540 including, but are notlimited to, carbon, cellulose, ceramic, cotton, glass, ion exchangeresin, metal, minerals, paper, nylon, polyethersulfone (PES), polyester,polypropylene (PP), polytetrafluoroethelyne (PTFE), polyvinylidenefluoride (PVDF), polyvinylidene chloride (PVDC), polysulfone, and sand.The filtration block 540 in one embodiment extends the full length of afluidic passage 360 and the sample 950 must pass through the filterblock 540 to move through the fluidic passage 360. In other embodiments,the filtration block 540 partially occludes the fluidic passage 360.

The filtration block 540 in other embodiments are impregnated with otherchemicals suitable for pre-treating the sample 950 prior to exposure tothe detector ligands 130 contained within the detector chambers 130. Theselection of chemicals for pre-treatment of the sample 950 is selectedaccording to the types of detector ligands 380 and analyte 960 beingused.

In still other embodiments, the filtration block 540 merely slows theflow of the sample 950 through the biosensor disk 500 in order tocontrol the amount of time the sample 950 spends inside a given detectorchamber 130 or fluidic passage 360 prior to passing to the next elementon the biosensor disk 500.

In another embodiment, the fluidic passage 360 is temporarily blockedusing a removable barrier 530, shown on the biosensor sensor disk 500with integrated detector chambers 130 in FIG. 5. The removable barrier530 is constructed of a material that absorbs the focused radiation 222from the disk system 200 and selectively weakens and breaks or vaporizessuch that flow of the samples 950 can be controlled from a state of noflow (removable barrier 530 intact) to a state where flow is allowed(removable barrier 530 is breached) using only the focused radiation 222from the disk system 200. In yet another embodiment, the removablebarrier 530 is positioned in proximity to either a passive heater 520 oran active heater 522 and the localized heating from those elementsremoves the removable barrier 530.

Active heaters 522 and sensors 524 can be operated using batterieseither placed within or on the biosensor disk 500, or alternativelypowered by the disk system 200 through either direct electricalconnections in the hub 264 or via radiation provided by the disk system200 to a receiver located on the biosensor disk 500. Active heaters 522provide similar localized heating of the sample 950 or various portionsof the detector chamber 130 and fluidic passages 360 to urge flow,encourage chemical reactions and binding to detector ligands 380, andotherwise control the flow of the sample 950 through the system.Additional sensors 524 can be integrated with other active elements,such as the active heaters 522 or passive heaters 520 to provideadditional capabilities such as temperature regulation.

There are multiple means for urging a sample 950 to pass through a givenbiosensor disk 500 with fluidic passages 360 and into or through adetector chamber 130. One means is the use of pressure applied to thesample 950 that urges the sample 950 to flow and occupy the fluidicpassages 360 and detector chambers 130.

A second means is the use of the centrifugal force generated by thespinning of the biosensor disk 500 in the disk system 200. The spinningof the biosensor disk 500 generates a body force on the sample 950urging the sample 950 to flow outward from the center or hub 264 towardthe outer edge 108. Another means for urging the sample 950 to flowthrough the biosensor disk 500, is the use of selective heating by apassive heater 520 or active heater 520 of the sample 950 in the fluidicpassage 360. The selective heating of some of the sample 950 within thefluidic passage 360 provides a motive force for urging the sample 950through the fluidic passages 360 and detector chambers 130 using buoyantor thermally driven forces. The selective heating can be augmented byvarious means of cooling the sample in order to maximize the thermalgradients and promote the thermally driven flow.

In yet another means, the fluidic passage 360 in the biosensor disk 500are configured to operate like a centrifuge to separate, mix, or evenprocess the analyte in order to maximize the response of the biosensorsystem 210. The biosensor disk 500 can easily exceed 180 rev/secondwhile being read using most commercial CD disk systems 200. Therotational velocity of the biosensor disk 500 can be used to move thesample 950 along the fluid passages 360 and the detector chambers 130through the body forces applied to the sample 950 caused by the rotationof the biosensor disk 500 in the disk system 200. The rotation of thebiosensor disk 500 is controlled by the structure of the informationencoded on the biosensor disk 500 or, in other embodiments, throughdirect control of the rotation system 266. In one embodiment, the sample950 is placed in the center of the biosensor disk 500 within the inputhub chamber 504. The input hub chamber 504 in another embodiment alsocomprises a chemical digestion chamber with chemicals adapted to freethe DNA or RNA or other proteins of a bacterial spore sample by chemicaldigestion of the basal layer and other membranes. The biosensor disk 500is rotated in some embodiments to encourage the operation of thechemical digestion chamber located in the input hub chamber 504. Afterthe chemical digestion process is complete, the biosensor disk 500 withinput chamber hub 504 is spun in order to separate and urge the sample950 toward fluidic passages 360 to the detector chambers 130. Thedetector ligands 380 located within the detector chambers 130 then bindto the analyte 960 contained within the sample 950 to form bounddetector ligands 480.

Still another means for urging the movement of the sample 950 is the useof an electrophoretic element 560 that creates an electric field over afluidic passage 360, as shown in the embodiment in FIG. 5. The electricfield created by the electrophoretic element 560 urges both theseparation of molecules within the sample 950 and the movement of thesample 950 through the passage due to the urge exerted by the electronicfield on the sample 950 and the constituent chemicals and materialswithin the sample 950. The electrophoretic element 560 in someembodiments is combined with a filtration block 540 to urge specificconstituent chemicals and materials in the sample 950, including in someembodiments the analyte 960, to separate.

All of these means for urging the sample 950 to move through the fluidicpassages 360 into and through the detector chambers 130 can be usedeither independently, or in combination by one of ordinary skill in theart to control the flow of the sample 950 through the biosensor disk500.

Process for Interrogating a Biosensor Disk with Computer

FIG. 7 provides a flow diagram outlining the process for using abiosensor system 210 to detect the presence of a specific analyte 960 byinterrogating a biosensor disk 100 that has been exposed to a sample950. The biosensor disk 100 has baseline data 902 encoded on thecontinuous data spiral 110. First, the biosensor disk 100 is exposed 700to the sample 950 containing the analyte 960. The biosensor disk 100exposed 700 to the analyte 960 is processed if necessary to encouragethe detector ligands 380 to bind to the analyte 960 and thereby formbound detector ligands 480. After the biosensor disk 100 is exposed 700,it is inserted 702 into the disk system 200, and nominally mated to thehub 264. The inserted 702 biosensor disk 100 mated to the hub 264 of thedisk system 200. The hub 264 is rotatably connected to the rotary motor264 thereby enabling the rotation 704 of the biosensor disk by the disksystem 200. The rotational speed of the biosensor disk 100 is controlledby the disk system 200.

After the biosensor disk 100 is rotating 704, the disk system 200 aligns706 the read write head or focusing lens 221 with the continuous dataspiral 110 encoded on the substrate 310 of the biosensor disk 100. Thealigned 706 focusing lens 221 emits 708 focused radiation 222 onto thesurface of the biosensor disk 100. The emitted 708 focused radiation 222penetrates the substrate 310 of the biosensor disk 100 to focus on aspot 250. The focused radiation 222 is reflected 710 back toward thefocusing lens 221 as reflected radiation 224. The reflected radiation224 is received 712 by the focusing lens 221 and directed toward theradiation sensor 240. The radiation sensor 240 then converts 716 thereflected radiation 224 into an electronic signal. The electronic signalis then sampled 716 by a computer at a predefined frequency. Thesampling 716 process in one embodiment is comprised of thresholding theelectronic signal converted 714 by the radiation sensor 240 to create abinary representation of the signal, i.e. either a zero or a one. Inanother embodiment the electronic signal is sampled 716 using amulti-bit analog to digital converter (ADC) to create a multi-bit,binary representation of the signal that corresponds to the intensity ofthe sampled 716 electronic signal.

In one embodiment, each separate radiation detector: upper left detector242, upper right detector 244, lower right detector 246, and the lowerleft detector 248 of the radiation detector 240 are averaged together asthey are converted 714 and the aggregate electronic signal is thensampled 716. In another embodiment, the electronic signal is converted714 from each of the separate radiation detectors 242, 244, 246, and 248into four channels. The electronic signal is sampled 716 on each of thefour separate channels and converted using either a thresholding processor a multi-bit analog to digital converter.

After the information reflected 710 from the biosensor disk 100 issampled 716, a computer stores and processes 718 the information. Thestorage and processing 718 includes matching of the sampled informationto the time interval embedded within the baseline data 902 encodedwithin the continuous data spiral 110 of the biosensor disk 100.Additional processing is performed as outlined below to interpret theinformation contained based on the reflected radiation 224 from thebiosensor disk 100 comprising information from the detector ligands 380,bound detector ligands 480, and pits 302 and lands 304 of one embodimentor the selective phase change of the writeable material 314 in anotherembodiment, coupled with the reflectively surface 340. In the case of alinear disk system 200, there is no reflective surface 340. The storedand processed 718 results are then output 720 for evaluation and reviewin graphical, audio, or tactile means.

Process for Interrogating a Biosensor Disk with Standard Audio Player

FIG. 8 provides flow diagram highlighting the process for using abiosensor system 210, comprising a standard consumer audio device, suchas a CD player, to detect the presence of one or more analytes 960 byinterrogating a biosensor disk 100 that has been exposed 700 to a sample950. The biosensor disk 100 in this embodiment has baseline informationencoded on the substrate 310, in either the pits 302 and lands 304 or inthe writeable materials 314 that corresponds to audio signals in digitalform suitable for use by a standard consumer audio device. The samesteps are used for interrogating the biosensor disk 100 with thestandard consumer audio device as used with computer from the initialsteps of exposing 700 the biosensor disk 100 to the sample 950 which mayor may not contain the analyte 960 through converting 714 the reflectedradiation 224 to an electronic signal. The electronic signal is sampled816 using a thresholding system to create a stream of zeros and ones orraw binary information. The raw binary information corresponds to therelative reflectivity of the biosensor disk 100 under the spot 250 atthe time of reading. While converting 816 the electrical signal, the rawbinary information is typically buffered to enable correlation of theraw binary information with the proper sampling frequency based on therate of information encoded on the continuous data track.

Part of converting 816 the electrical signal into an aural electronicsignal is the conversion of the raw binary information to digital data.The baseline data 902 stored on the continuous data spiral 110 of thebiosensor disk 100 is encoded using eight to fourteen (EFM) modulation.The EFM system is described in greater detail below, has the practicaleffect of the standard is to map the raw binary information read fromthe surface of the continuous data spiral 110 as 14-bit information into8-bit digital words corresponding to upper and lower bytes of an audiosignal which provides some protection against single-bit errors becauseonly 256 of the 16,384 combination are allowable. The 8-bit digitalwords are reconstructed into audio digital signals using the dataconversion standards described in greater detail below. The bounddetector ligands 480 effect the digital audio signal while beingconverted 816 in multiple ways, including the introduction ofunrecoverable errors E32 errors and by changing the 8-bit digital wordcoming from the conversion 816. These E32 errors and modifications tothe 8-bit digital words arising due to the effect of the bound detectorligands 480 on the transmission of the focused radiation 222 through thedetector chamber 130 impacts the converted 816 aural electronic signals.The aural electronic signals are output 818 using a combination ofdigital to analog converters (DAC) and amplifiers as an analog waveformcorresponding to the reflected radiation 224 received from the biosensordisk 100 as a function of the baseline data 902 encoded in thecontinuous data spiral 110 coupled to the effect of the bound detectorligands 480. The aural electronic signals are fed 820 to a speaker thatconverts the electronic input to audio waves. The audio waves travelthrough the air 822 and are heard 824. In the case of the a human being,the audio waves are heard 824, and the effect of the bound detectorligands 480 manifests as a distinct individual or series of pops,interruptions, frequency shifts, or other disturbances in the signal. Insome embodiments, the detection of the analyte 960 in the sample 950results in the consumer audio player being unable to play the biosensordisk 100 and displaying an error.

Process for Integrating Separate Detector Substrate with Substrate

FIG. 9 graphically illustrates the process steps associated with thefabrication and integration of a substrate 310 with continuous dataspiral 110 comprised of a pregroove 308 and a writeable material 314with no specific baseline information, referred to as a blank writeablesubstrate 900, with a detector substrate 350.

The blank writeable substrate 900 is comprised of a substrate 310 withpregroove 308, writeable material 314 and reflective material 340. Theblank writeable substrate 900 is encoded with baseline data 902 tocreate a baseline data substrate 904 using an encoding process. Theencoding process 980 uses focused radiation 222 to selectively burnaway, ablate, or change the phase of selected portions of the writeablematerial 314 to adjust the amount of reflected radiation 224 convertedby the radiation detector 240, thus storing baseline data 902. Thebaseline data 902 is selected based on the configuration of detectorchambers 130 and fluidic passages 360 selected for the detectorsubstrate 350 as well as the type of detector ligands 380 and therelative absorption of the bound detector ligands 480 to the focusedradiation 222 used by the disk system 200.

The baseline data substrate 904 has a series of interlocking features,920, 922, 924, and 926. The interlocking features in this embodimentinclude a semi-circle 920, a triangle 922, a trapezoid 924, and a square926. These interlocking features 920, 922, 924, and 926 are adapted tofit within the corresponding interlocking receptors 910, 912, 914, and916 on the detector substrate 350, enabling the detector substrate toslide into and become substantially rigidly affixed 988 to the baselinedata substrate 904. In other embodiments the interlocking features arereversed with the interlocking receptors 910, 912, 914, and 916 locatedon the baseline data substrate 904 while the interlocking features 920,922, 924 and 926 are located on the detector substrate 350.

A blank detector substrate material 952 is used to create the detectorsubstrate 350. The blank detector substrate 952 is comprised ofdifferent materials based on the type of detector ligands 380, analyte960 and focused radiation 222 used to read the biosensor disk 100. Theblank detector substrate 952 materials are selected from the materialsdescribed above, including but not limited to polycarbonate,polystyrene, and silicon. The blank detector substrate 952 undergoes afabrication process 982 to create the detector chambers 130, andoptionally other fluidic structures including, the fluidic passages 360,and microfluidic control structures such as filtration block 540,removable barrier 530, passive heaters 520, active heaters 522,electrophoretic elements 560, and additional sensors 524 as needed fordetecting the one or more analytes 960. In the case of silicon, thefabrication process 982 can comprise multiple steps to create a varietyof different fluidic structures and detector chambers 130 desired toprocess a given sample 950 to determine the analyte(s) 960 containedtherein. The silicon fabrication process 982 can utilize standardmicroelectromechanical systems (MEMS) or microsystems technology (MST)fabrication techniques in addition to microelectronic fabricationtechniques as described in greater detail above. For embodimentsconstructed from plastic, such as polycarbonate or polystyrene, thefabrication process 982 is nominally a thermal assisted molding process,or injection molding process, as described in greater detail above.

The fabrication process 982, in this embodiment, also creates theinterlocking receptors 910, 912, 914, and 916 that interlock with theinterlocking features 920, 922, 924, and 926 respectively. Theinterlocking receptors include an interlocking semi-circle 910 receptor,an interlocking triangle 912 receptor, an interlocking trapezoid 914receptor, and an interlocking square 916 receptor.

After creating the detector substrate 350, the next step in the processfor creating an integrated biosensor disk 100 is to affix the detectorligands 380 to the detector chambers 130 on the detector substrate 350.In the case of embodiments where the detector chambers 130 areintegrated with the substrate 310, the fabrication process 982 isapplied to the substrate 310 to create both the continuous pregroove308, or alternatively is used to create the pits 302 and land 304 alongthe continuous data spiral 110 necessary to create the baseline data 902for interpreting the results during the same fabrication process thatcreates the detector chambers 130.

Process for Binding Detector Ligands to Detector Chamber

The binding process 984 for binding detector ligands 380 to the detectorchamber 130 varies according to the detector substrate material 350, thedetector ligands 380 being used and the process steps required to affixthe detector ligands 380 to the surface of the detector chambers 130.

Detector Ligand Selection

The detector ligands 380 that are used to bind to the analyte 960 forform bound detector ligands 480 are selected from a wide range ofdifferent classes of compound known to those of ordinary skill in theart.

In one embodiment, the detector ligands 380 are selected to detect oneor more analytes 960 in a sample 950. Common system for detector ligands380 are based on avidin/streptavidin-biotin systems. These systems canbe used for enzyme immunoassay systems, glycoconjugate analysis, and DNAdetection systems. One embodiment of creating the detector ligands 380utilizes a labeled avidin-biotin system. The labeled avidin-biotinsystem uses a biotinylated primary antibody bound to the detectorchamber 130 to create the detector ligand 380. The primary antibodybinds with the antigen by incubating the sample 950 in the detectorchamber 130 with the addition of an avidin-enzyme conjugate. Theadditional avidin enzyme conjugate can be added to the detector chamber130 through a secondary addition of fluids, or by opening a removablebarrier 530 and allowing the avidin-enzyme conjugate to enter thedetector chamber 130. The avidin-enzyme conjugate changes the relativetransmissivity of the bound detector ligand 480, thereby enabling thedisk system 200 to distinguish the presence of the analyte 960 due tothe reduced reflected radiation 224 at a specific spot 250 correspondingto the detector chamber 130 with the bound detector ligand 480 using thelabeled avidin-biotin system. In an alternative embodiment, the avidinenzyme of the labeled avidin-biotin system responds to the focusedradiation 222 by fluorescing or reflecting the reflected radiation 224to a greater extent or by increasing the transmissivity of the bounddetector ligand 480 relative to the unbound detector ligand 380, therebyindicating that there is a bound detector ligand 480 through theincreased reflected radiation 224 at a given spot 250. All of the systempresented herein provide feedback on the presence of the analyte 960through either decreased transmissivity, or increased transmissivity orincreased reflectance, thereby changing the relative reflected radiation224 detected by the radiation detector 240.

A second type of avidin/streptavidin-biotin system for use as a detectorligand 380 used a bridged avidin-biotin system. The bridgedavidin-biotin system uses avidin as a bridge between a biotinylatedsecondary antibody and a biotinylated enzyme that is used to change thetransmissivity or reflectivity of the bound detector ligand 480 so thatbound detector ligand 480 can be picked up by the disk system 200.

In both of these avidin/streptavidin-biotin systems, the detector ligand380 is bound as part of the binding process 984 to a detector chamber130 using processes known to one of ordinary skill in the art. In oneexample, a specific detector chamber 130 or detector chambers 130 formultiple sensitivity are selected for application of the given detectorligand 380. The detector chamber 130 is first prepared to ensure thereare residual materials or chemicals remaining from the fabricationprocess 982. In this embodiment, a temporary protective cover is placedover the other areas of the detector substrate 350 in preparation forapplication of the detector ligands 380 and to protect detector ligands380 that have already been integrated with the detector substrate. Inother embodiments, robotic dispensers are used to precisely deposit thefluids into the detector chambers 130. For the first step a suitablesubstrate for immobilizing the detector ligands 380 must be created. Inthe case of silicon, this can be accomplished by a number of means knownto those of ordinary skill in the art including, but not limited to,introducing an activated carboxyl group on the surface of a diamond likecarbon coated (DLC) silicon forming the detector chamber 130. Manypolymers are activated by oxidating the polymer materials forming theinside of the detector chamber 130 using an organic acid. After thedetector chamber 130 is prepped for binding to the detector ligand 380,the detector ligand 380 is introduced into the detector chamber 130. Thedetector ligand 380 is held at an elevated temperature to promotebinding of the detector ligand 380 to the prepared surface of thedetector chamber 130. Typically the more concentrated the solution ofdetector ligands 380, the longer the hold, and the better activated thesurface of the detector chamber, all impact the adhesion of the detectorligands 380 to the detector chamber 130. After the detector ligands 380are affixed to the detector chamber 380, the detector substrate 380 isready for exposure to the sample 950 that may or may not contain one ormore of the analytes 960.

There are many other types of detector ligands 380 that can beintegrated with the detector chambers 130 of the biosensor disk 100. Theselection of specific types of detector ligands 380, the chemistry ofthe detector ligands 380, and the binding of the detector ligands 380 tothe biosensor disk, and the process for exposing the detector ligands380 to the sample 950 will vary according to the type of analyte 960 tobe detected and the capabilities of the disk system 200, including butnot limited to the diameter for the spot 250, the configuration of thedisk system 200, e.g. linear, non-prismatic, or prismatic, the sensitiveof the radiation detector 240, and the characteristics of the focusedradiation 222 used to detect bound detector ligands 480. Some examplesof alternative detector ligands include:

-   -   A detector ligand 380 formed from complementary DNA (cDNA)        produced from cellular messenger RNA using reverse transcription        polymerase chain reaction (RT-PCR) to enable detection of        messenger RNA.    -   A detector ligand 380 formed using DNA spotting technology using        oligonucleotide genome sets;    -   Peptide based detector ligands 380 with receptors optimized to        bind to specific metals or chlorinated substances.        Exposure of Detector Substrate to Sample

Referring again to FIG. 9, the detector substrate 350 with detectorligands 380 placed inside the detector chambers 130 is ready to beexposed 986 to the sample 950. The sample 950 in this embodiment iscontained within a sample chamber 906. The detector substrate 350 isexposed 984 to the sample 950 that may or may not contain the analytes960 by emersion in the sample chamber 906. The detector substrate 350 isheld inside the sample chamber 906 for sufficient time to ensureadequate wetting of the detector chambers 130. After the detectorsubstrate 350 is wetted, it is removed from the sample 950 and anysecondary processes necessary to ensure binding of the analyte 960 tothe detector ligands 380 is performed. In other embodiments, the sample950 is taken from the sample container 906 and placed on the detectorsubstrate 350 using the fluidic passages 360 described above, includingbut not limited to the top surface input passage 506, the bottom surfaceinput passage 508, the input hub chamber 504, and directly into thedetector chambers 130.

Integration of the Baseline Data Substrate with the Detector Substrate

The encoding process 980 for the embodiment shown in FIG. 9 is performedprior to integration of the baseline data substrate 904 with the exposeddetector substrate 350. During the assembly process 924, the adhesivebacking (not shown) on the exposed detector substrate 350 is removed.The exposed detector substrate 350 is aligned with the inside of thebaseline data substrate 904 and aligned so the interlocking receptors910, 912, 914, and 916 on the exposed detector substrate 350 accept theinterlocking features 920, 922, 924, and 926 and pushed into thebaseline data substrate 904 along the arrows 9A. Once the exposeddetector substrate 350 is affixed to the baseline data substrate 904,the biosensor disk 100 is ready for analysis to determine the presenceof the analyte 960 in the sample 950. Alternative orders for assembly ofthe substrate 310 with the detector substrate 350 are integrated intothe biosensor disk 100 and exposure of the biosensor disk and/or thedetector substrate 350 to the sample 950 are apparent to those ofordinary skill in the art.

Variable Thickness Detector Substrate

In yet another embodiment of the detector substrate 350, the material ofthe detector substrate 350 is changed in the vicinity of the detectorchamber 130. The material change can be either substitution of amaterial with a different refractive index in the vicinity of thedetector chamber 130 or alternatively a lens shaped structure in thevicinity of the detector chamber 130 necessary to ensure the spot 250 ofthe focused radiation 222 falling on the continuous data spiral 110remains approximately the same size regardless of whether the spot 250is traveling over a detector chamber 130 with less material between thetop surface 140 and the continuous data spiral 110 or over an area withthe nominal amount of material between the top surface 140 and thecontinuous data spiral 110 to the lack of a detector chamber 130 locatedtherein. Varying the refractive index or thickness of the detectorsubstrate 130 enables relatively constant reflected radiation 224thereby minimizing the risk of excessive excursion of the focusing lens221 by the lens position 220 attempting to refocus the focused radiation222 over a detector chamber 130.

Baseline Information on Continuous Data Track

In the embodiments shown in FIGS. 3, 4 and 5, the background informationis stored on the continuous data spiral 110 using the combination ofpits 302 and lands 304 of a permanently recorded continuous data track100 or alternatively with the different phase change or burned off areasof material that provide different reflectivity from the unchanged dataencoding material 314. The radiation spot 250 directed to the surface ofthe continuous data track 110 is reflected back to the disk system 200different depending on whether or not the radiation spot 250 is directedon a pit 302 or land 304 or a part of the material where it has changedphase or has been burned away. The amount or flux of reflected radiation224 detected by the radiation detector 240 thus changes as the radiationspot 250 moves over the continuous data spiral 110. Each time the totalradiation flux on the radiation detector 240 changes, the output of theradiation detector 240 rises or falls depending on its locating eitherpit 302 to land 304 transition or a land 304 to pit 302 transition. Thechange of total radiation flux can thus be used to encode and capturebinary information in the surface of the biosensor disk 100. In theembodiment of the disk system 200 shown in FIG. 2, the radiationdetector 240 can be used to average of the signals from all fourdetectors (242, 244, 246, and 248). As the average reading from all fourdetectors either dips or rises, the change is characterized as either a0 or 1. In this manner binary information is encoded on the surface ofthe biosensor disk 100.

Information is recorded in the pits 302 and land 304 or using thecontinuous pregroove 308 and the writeable material 314 by the amount oftime spent as either a zero of a one. The standard used by standard CDsand DVDs to encode data uses eight to fourteen modulation (EFM). The EFMsystem avoids pits 302 that are too short, too close together, or toolong by requiring that there are always at least two 0 bits between any1 bit, and ensuring there are no more than ten 0 bits between any 1 bit.Therefore the size of any given pits 302 or land 304 is never smallerthan 3T (T defined as the time necessary to encode a single bit of data)and never longer than 11T. With standard CD velocities and spacing, thismeans that the smallest pit 302 or land 304 is between about 278 nm toabout 324 nm, while the largest pit 302 or land 304 is between about3054 nm to about 3563 nm.

Error Correction System of Standard CD Type Read/Write Systems

EFM encoding is sequentially applied to a series of bytes called aframe. A frame holds 24 bytes of user data, 1 byte of subcode data, and8 bytes of parity (error correction), for a total of 33 bytes. Eachframe as encoded on the continuous data spiral 110 is preceded by a24-bit synchronization pattern and 3 merging bits. The sync data has aunique pattern not found elsewhere on continuous data spiral 110, and itensures the disk system 200 correctly finds the start of the frame. Thepattern is in binary form [100000000001000000000010] or threetransitions separated by 11T, which can't occur otherwise because themerging bits are specifically chosen to prevent it. The sync dataprovides a means for the disk system 200 to locate specific informationon the surface of the biosensor disk 100.

The rest of the 33-byte frame is read as 14-bit EFM values followed by 3merging bits. Therefore a total of 588 (24+3+(14+3)*33) raw binary bitsare encoded in the channel frame. The merging bits are removed from thechannel frame followed by an EFM decoding process recreates the 8-bitdata from the 14-bit data contained within the channel frame to createthe F3 Frame. The subcode byte is removed to create the F2 Frame that ispassed to a Cross-Interleave Reed-Solomon (CIRC) decoder. The CIRCdecoder processes the F2 Frame through two cascaded error correctionstages, C1 and C2. Errors within each error correction state areindicated the letter E followed by the type of error (i.e. 1=singlesymbol correctable errors; 2=−double-symbol correctable errors, and 3indicates triple-symbol uncorrectable errors) and the CIRC decoder stateof the error. For example, an error code of E31 or E32 indicates anuncorrectable error in the C1 and C2 decoder stages respectively. Thesum of the E11, E21, and E31 over one second, averaged over 10 secondsof data provides a measure of BLER or block error rate. BLER provides anestimate of the number of errors located at the C1 stage of the CIRCdecoder. Since BLER and C1 stages errors are indicative of primarilysingle bit errors, most bound detector ligands 480, since they aresignificantly larger than even the maximum size encoded raw physical bit(11T) may cause significant C1 and BLER errors, however it is harder todistinguish.

The E12 count indicates the number of single-symbol (correctable) errorsin the C2 decoder. The sum of E21 and E22 form a burst error count(BST), which can be used to identify the present of bound detectorligands 480 on a biosensor disk 100.

E32 errors, representing triple-symbol (uncorrectable) errors in the C2decoder, results in damaged data being read from the baseline datatrack. For an audio disk system 200 an interpolation is performedbetween the prior non-E32 frame and the next non-E32 frame to minimizethe effect of the E32 error. This interpolation requires the amount ofdisplaced data from a bound detector ligands 480 to be relatively large,or the changes in the baseline data 902 to be large in order to maximizethe potential for a given interpolation to be heard 824. The likelihoodof the bound detector ligands 480 to generate an audible signal in thepresence of the error correction is increased by locating multipledetector chambers 130 across a number of successful physical data tracks112.

In embodiments with computer processing the resulting data directinspection of the digital errors are possible and it is possible tocorrelate the relative errors rates for a specific frame of data to therelative expression of detector ligands 380 in a given detector chamber130.

In either embodiment of the biosensor disk 100, regardless of whetherinformation is encoded using a writeable material 314 or using a seriesof pits 302 and land 304 located in the substrate 310, the biosensordisk 100 is encoded with baseline data 902. The baseline data 902 isselected to provide a discriminating signal using knowledge of the disksystem 200, including the methodology for encoding raw binaryinformation in the baseline data 902 and the decoding and errorcorrection schemes applied to the baseline data 902 as it is receivedfrom the biosensor disk 100 while it is read by the disk system 200. Thediscriminating signal encoded in the baseline data 902 provides abackground information suitable for distinguishing the impact of thebound detector ligands 480 on the reflected radiation 224, therebyproviding feedback to the user regarding the relative expression ornumber of bound detector ligands 480 present in the system.

The baseline data 902, in some embodiments also contains informationencoded about the type of sensor being queried on a given logical track.The logical track is a superset of physical tracks 112 and a subset ofthe continuous data spiral 110 that comprise information related to thesame information. In addition to providing information about the type ofdetector chambers 130 and detector ligands 380 located along a specificlogical track on the continuous data spiral 110, the baseline data 902provides a background digital signal from the reflected radiation 224that the bound detector ligands 480 interrupt in a known way. Theinterruption caused by the bound detector ligands 480 interacts with thedisk system 200, including the error correction and encoding systems, tocreate a signal that is processed and presented to the user or processedand output 818 as aural signal for generation 820 by a speaker intoaudio waves that travel 822 through the air so the changes caused by thebound detector ligands 830 to the baseline data 902 are heard 824.

Sectional Substrate Method for Detection Through Digital SubstrateInterference and Interrogation Method

In still other embodiments, the analyte detector region 120 has detectorligands 380 micropatterned 1002 onto the surface of the analyte detectorregion 120. The detector ligands 380 are preferably micropatterned 1002to be approximately at or just below the detection threshold of thesystem, such that when an analyte 960 is present the path for returnedlight from the continuous data spiral 110 is interrupted sufficiently toproduce at least one detectable error, for example a C1, C2 or CU error,when the continuous data spiral 110 is read by the system.

In one embodiment, the micropatterning 1002 is accomplished by utilizinga photochemical process, for example using a chrome plated quartz maskas is known in the art. An SiO2 substrate with a grown oxide layer, suchas one commercially available from 3M, is cleaned and sterilized 1102using, for example, pyrogenic steam. Then the surface is nitrogen dried1104 and inserted into a 2% Silane, Si(CH2)3, solution 1106, incubatedand then sonicated in acetone 1108 before being nitrogen dried again1110. Heating to 120 degrees Celcius 1112 produces a dense smoothsubstrate of Silane, Si(CH2)3, on SiO2. Applying photoactivatable biotin1114, for example using the one commercially available from Pierce, in a2:9 solution with deionized water, one then presses it with a glass slipand bakes dry at 37 degrees Celcius 1116. Finally, the micropatternedchrome plated quartz mask is placed 1118 over the photoactivatablebiotin and exposed 1120 to 365 nm light at 15 mW/cm2 for four minutes,before rinsing 1122 with a phosphate buffered saline tween-20 (PBST)multiple times to remove any unactivated biotin. The surface is thenexposed 1124 to 1:5 diluted Avidin for 30 minutes and rinsed again withPBST 1126. Commercially available biotinylated antibodies are then putonto the micropatterned regions 1128, for example using a micropipet,and incubated 1130 at 25 degrees Celcius before being dried with astream of nitrogen gas 1132.

In other embodiments, micropatterning 1002 is accomplished bymicrocontact printing, or spotting or spraying of ligands onto theanalyte detector region 120. In some embodiments, the micropatterning1002 is performed on a polycarbonate analyte detector region 120. Inother embodiments the analyte detector region 120 utilizes SiO2 for amore durable surface for performing the micropatterning 1002. Forexample, in some embodiments, a nanometer layer of photobiotin can beapplied to untreated SiO2 by applying the photobiotin and then dryingthe SiO2 at approximately 370 C. SiO2 allows analyte detector regions120 as thin as 0.25 mm or thinner to be successfully utilized. BecauseSiO2 has an index of refraction of 1.45 which is different thanpolycarbonate, in some embodiments the SiO2 is treated with nitrogenuntil the SiO2 contains approximately 3% nitrogen at which point it willhave an index of refraction (IR) approximately equal to the IR 1.55 ofpolycarbonate. The index of refraction is more important for reflectiontype CD/DVD systems than for a modified system that uses a transmissionapproach.

In some embodiments, such as when using a microfluidic channel 360, theSiO2 is treated so that it becomes more receptive to the application ofphotobiotin and hydrophobic films. Use of hydrophobic films prevents thesample 950 from adhering to any part of the analyte detector region 120except the detector ligands 380, ensuring that any the blockage ofreturned light is the result of analytes 960 in bound detector ligands480 and not due to any extraneous fluid sample 950 that is still presentin the analyte detector region 120, or an unbound substance of nointerest from the fluid sample 950. To prepare the SiO2, pyrogenic steamis first applied to the surface to clean and sterilize, then the surfaceis nitrogen dried and exposed to Silane, Si(CH2)3, at approximately 1050C, and thereafter cooled, creating an approximately 260 nm layerreceptive to the application of photobiotin or another hydrophobic thinfilm. In another embodiment, Silicon Nitride, Si3N4, is applied to theSiO2 by plasma chemical vapor deposition. Silicon Nitride, Si3N4, andSilane, Si(CH2)3, have RIs of approximately 1.46, and it is possible tohave an even lower RI in some configurations, for example an RI of 1.33when a fluid sample is present in a 10 micrometer channel. Therefore, insome embodiments, polyvinyl alcohol or glycol alcohol are included inthe sample 950 or added prior to analyzing in order to increase the RIcloser to the RI 1.55 of polycarbonate.

In one embodiment the analyte detector region 120 includes detectorligands 380 in a gel or gel-like detection substrate 1004. In anotherembodiment, the detector ligands 380 are in the form of a thick or thinfilm detection substrate 1004. The detection substrate 1004 is thendocked with the rest of the disk 100 in a socket abutting the datasubstrate 1006 of polycarbonate that supports the continuous data spiral110.

In one embodiment, the system uses an unmodified CD/DVD player of acomputing device. Most computer CD/DVD players allow applications accessto the C1 (Bit Error), C2 (Block Error), and CU (Unrecoverable Error)errors of the CIRC decoding engine which decodes the raw data retrievedfrom the disk and converts it into usable binary data for applications.Generally, however, applications do not have low level access to the rawdata itself, only the usable binary data and the errors. When pits 302and lands 304 in the continuous data spiral 110 are blocked, for exampleby one or more bound detector ligands 480, a C1 error is generated. Ifmultiple pits 302 and lands 304 are blocked, a more serious C2 error isgenerated. Generally, the system can recover the underlying data on thedisk for C1 and C2 errors. However, if too much of the data is blocked,the system will generate a CU unrecoverable error.

The detector region 120 is micropatterned 1002 with detector ligands380, and exposure of the detector ligands 380 to analytes 960 createsbound detector ligands 480 which block pits 302 and lands 304 in thecontinuous data spiral 110 causing errors to be generated. In oneembodiment, the detector ligands 380 are small enough that they, bythemselves, do not generate C1, C2 or CU errors. In another embodiment,the detector ligands 380 generate a small baseline number of C1 errors.In both embodiments, when the detector ligands 380 attach to analytes960 to become bound detector ligands 480, the bound detector ligands 480generate a greater number of C1 errors that the detector ligands 380generate alone. This relative difference, or delta, in the number oferrors is utilized by the system as an indication that the analyte 960of interest is present in the sample 950. The bound detector ligands 480may also generate a number of C2 errors. In one embodiment, the numberof C1 and C2 errors can be utilized to indicate relative concentrationsof analytes 960 in the sample 950.

In one embodiment, the continuous data spiral 110 is written with datain a pattern that tends to create a random distribution of lands 304 andpits 302, thus preventing clustering of lands 304 or pits 302 inadjacent tracks and any associated detection artifacts that would arisedue to the clustering. In an alternate embodiment, the data is writtenso as to maximize the number of land-to-pit and pit-to-land transitions,thus maximizing the possibility that blockage by a bound detector ligand480 will create a detectable error.

The shape of the micropatterning 1002 is also partially determinative ofthe sensitivity of the system to bound detector ligands 480. In oneembodiment, the micropatterning 1002 is linear in shape havingapproximately radial, tangential or other orientations, or combinationsthereof. In another embodiment, the micropatterning 1002 is curvilinear,for example by tracking the continuous data spiral 110. Micropatterning1002 using approximately curvilinear patterns allows detection of bounddetector ligands 480 as small as 10 um by 6 um, whereas radial linearpatterns allows detection of 15 um×8 um bound detector ligands 480 andtangential linear patterns allows detection of 13 um×7 um bound detectorligands 480. In one embodiment, the system can detect individual bounddetector ligands 480. This is typical when the analyte 960 andassociated bound detector ligand 480 is large in comparison toindividual pits 302 and lands 304. In another embodiment the detectorligands 380 are clustered together such that clusters of bound detectorligands 480 are utilized to trigger at least one C1 error. This isuseful for detecting smaller analytes 960 wherein a single associatedbound detector ligands 480 may not be large enough to trigger a C1 errorreliably by itself.

Additionally, clusters of detector ligands 380 can be specificallymicropatterned to block pits 302 and lands 304 and cause errors in aspecific detectable pattern and can therefore serve as markers for thesystem to determine which close by detector ligands 380 are detectingwhich analytes. For example, a cluster specifically micropatterned 1002to generate a specific number of C1 errors in a row would identify oneanalyte 960 detection site, whereas a cluster micropatterned 1002 togenerate a pattern of high-low-high-low C1 errors in a row wouldidentify a different analyte 960 detection site. These clusters wouldpermit alignment of analyte 960 detection sites without having to alsoline up data markers in the underlying continuous data spiral 110.Typical micropatterning techniques for binding proteins to surfacesinclude photochemical, micro-contact printing, micro-fluid network, andspotting or spraying proteins onto a surface. For example, for thephotochemical method, a chrome plated quartz mask is used to produce aspecific micropattern of detector ligands 380.

In one embodiment the detector region 120 is roughly rectangular withparallel sides and is placed in a corresponding socket in the biosensordisk 100. In another embodiment, the detector region 120 is roughlypie-slice shaped and has sides that diverge the further they aredisplaced from the center 101, for example the sides can be portions ofa radius of the biosensor disk 100. In another embodiment, the detectorregion 120 is circular in shape and is placed over the underlying diskto form the biosensor disk 100. In some embodiments, the detector region120 forms an internal chamber between it and the rest of the biosensordisk 100 and may include a fluid channel 360, whereas in otherembodiments the detector region 120 is an exposed surface application.

In alternate embodiments, the error correction and CIRC circuitry isbypassed, allowing direct access to the raw data stored on thecontinuous data spiral 110. The raw data would be compared with areference data to determine which pits 302 and lands 304 were beingblocked and therefore which detector ligands 380 had associated analytes960 attached to them. In another embodiment, the data on the underlyingcontinuous data spiral 110 could be specifically encoded or burned tothe disk with errors such that blocking of certain pits 302 and lands304 would force erroneous error correction by the error correction andCIRC circuitry. In this embodiment, the resulting data from the CIRCwould be compared with a reference data to infer which pits 302 andlands 304 were being blocked and causing the erroneous CIRC correctionand therefore which detector ligands 380 had associated analytes 960attached to them. These alternate embodiments have the advantage thatthe system could detect the detector ligands 380 even when they are inthe code and subcode sections of the continuous data spiral 110, but mayresult in the system not being compatible with all hardwaremanufacturers and CD/DVD players.

In another embodiment, analytes 960 are collected in a solution that isapplied to the analyte detector region 120. The solution is allowed todry prior to scanning the biosensor disk 100. As the solution dries,analytes 960 cluster near the edge and form a discernable ring thatblocks pits 302 and lands 304 in the continuous data spiral 110,allowing detection of the presence of the analytes 960 in the solution.In embodiments the solution is water, an alcohol such as isopropylalcohol, a mixture of water and alcohol, or a solvent.

Referring now to FIG. 12, a first experimental configuration 1200 ispresented. First, a clean scan 1202 of the baseline data 902 of abiosensor disk 100 is performed. The clean scan 1202 is performed priorto exposure of the biosensor disk 100 to analytes 960 in order todetermine the number of C1, C2 and CU errors in the baseline data 902itself. It is normal for CDs and biosensor disks 100 to have flaws inthe baseline data 902 that results in a low number of correctable C1errors per sector detected during the clean scan 1202. Next, a singledrop of a solution of water and isopropyl alcohol containing 3 μmpolystyrene microspheres 1208 was applied to the analyte detector region120 using a micropipette. The 3 μm polystyrene microspheres 1208 areused to represent a microorganism being detected or even an analyte 960.The single drop was approximately 0.1 μl and assumed a circular geometryapproximately 0.7 mm in diameter. As the water in the 0.1 μl solutionbegan to dry, it produced a circular ring 1206 having a highconcentration of 3 μm polystyrene microspheres 1208. Removing theremainder of the solution, left a circular ring 1206. A secondmicrosphere scan 1204 is performed on the biosensor disk 100 that inFIG. 12 illustrates the increase in C1 errors due to the circular ring1206 of 3 μm polystyrene microspheres 1208. The experimentalconfiguration 1200 was performed for solutions containing 3 μmpolystyrene microspheres 1208 at concentrations ranging from about 2.65%down to about 0.12%. Detection of increased C1 errors was possible downto about 0.15% solutions of 3 μm polystyrene microspheres 1208.

Referring now to FIG. 13, a second experimental configuration 1300 ispresented. After the clean scan 1202 of the baseline data 902 of abiosensor disk 100 is performed, a curved section of material, forexample an edge of a polycarbonate disk, was placed against the analytedetector region 120 at a planar angle of 15°. A single drop of asolution containing 3 μm polystyrene microspheres 1208 was applied todetector region 120 where the curved section of material was touchingthe analyte detector region 120 and allowed to dry. As the water in the0.1 μl solution began to dry, it produced a curved arc 1302 having ahigh concentration of 3 μm polystyrene microspheres 1208. A microspherescan 1304 of the curved arc 1302 performed on the biosensor disk 100illustrates the increased number of C1 errors due to the curved arc 1302of 3 μm polystyrene microspheres 1208. The second experimentalconfiguration 1300 was performed for solutions containing 3 μmpolystyrene microspheres 1208 at concentrations ranging from about 2.65%down to about 0.10%. Detection of increased C1 errors was possible downto about 0.11% solutions of 3 μm polystyrene microspheres 1208.

The first experimental configuration 1200 and the second experimentalconfiguration 1300, illustrated in FIGS. 12 and 13, show the circularring 1206 and curved arc 1302 at approximately right angles to theunderlying continuous data spiral 110 of the baseline data 902 of thebiosensor disk 100. By patterning the circular ring 1206 and curved arc1302 along the continuous data spiral 110 lower concentrations ofsolutions can be used that allow detectable levels of increased C1errors. Both the first experimental configuration 1200 and the secondexperimental configuration 1300 illustrate methods of producingdetectable increases of C1 errors over a clean scan 1202.

Referring now to FIGS. 14 and 15, in another embodiment a microsphereenhanced detection system 1400 and microsphere enhanced detection method1500 are presented. In these embodiments, coated microspheres 1402enhance detection of analytes 960 in the bound detector ligands 480.Coated microspheres 1402 are readily available as being coated witheither biotin or Streptavidin. This choice in coated microspheres 1402makes it easier to select the appropriate coated microsphere 1402. Thecoated microspheres 1402 can therefore bind with a wide variety ofproteins (i.e. Ig) depending on the process required to generate astrong non-covalent bond which is inferior to the binding site of theprotein in question (i.e. the antigenic determinant.) Therefore, ininstances where a protein can be more easily or cost-effectively boundto Streptavidin, a biotinylated microsphere would be utilized—or theopposite—a sphere coated with Streptavidin would obviously be applied ininstances wherein it was easier to create a ligand using biotin. Coatedmicrospheres 1402 should therefore be read broadly to include bothbiotinylated microspheres, Streptavidin coated microspheres, andmicrospheres 1208 having attached detector ligands 380.

In these embodiments, an analyte detector region 120 includes detectorligands 380 in a gel or gel-like detection substrate 1004. In alternateembodiments, the detector ligands 380 are directly attached or patternedto the analyte detector region 120. The analyte detector region 120 anddetector ligands 380 are then exposed 1502 to the analytes 960. Thiscauses the analytes 960 to bind 1540 to the detector ligands 380 to formbound detector ligands 480. Next the analyte detector region 120 andbound detector ligands 480 undergo a second exposure 1506 with coatedmicrospheres 1402. In an embodiment, the coated microspheres 1402 areexposed 1506 to the bound detector ligands 480 using a solution ofde-ionized water, which is then dried or removed. The coatedmicrospheres 1402 bind 1508 to the bound detector ligands 480 or theanalytes 960. The detector substrate 1510 is then attached 1510 to thebiosensor disk 110, and the biosensor disk 110 is scanned 1512. Thecoated microspheres 1402 increase the number of detectable errors duringthe scan 1512 of biosensor disk 110 and attached analyte detector region120. For example, a polystyrene coated microsphere 1402 will readilyabsorb or diffract light energy of the source radiation 204 from aradiation emitter 202 of the disk system 200 that scans 1512 thebiosensor disk 110.

In embodiments, the coated microspheres 1402 are biotin-coated 3 μmpolystyrene microspheres 1208. In other embodiments, the coated 1402microspheres are between 1 μm and 10 μm spheres of polystyrene, latex orother materials as would be known or understood in the art. The bindingprocess for attaching the biotin to the microsphere 1208 can beperformed similar to the binding process used to attach detector ligands380 to the analyte detector region 120, and can be performed byimmersion of the coated microsphere 1402 in a solution containingdetector ligands 380. In embodiments, coated microspheres 1402 areexposed to and coated with steptavidin-tagged protein, for example animmunoglobulin. In embodiments the coated microspheres 1402 have one ormore identities of binding-proteins. For example, the coatedmicrospheres 1402 may have a combined spectrum of Igs targeted to thevariants of E. coli. In embodiments, the detector ligands 380 on theanalyte detector region 120 can be separated into different detectionregions, or zones, each associated with one or more variants of E. coli.In this manner, a coated microsphere 1402 having combined spectrum ofIgs attaches to the bound detector ligands 480 or analytes 960 in any ofthe detection regions, or zones, while each detection region is onlyassociated with one (or more) variants of E. coli. This reduces thenumber of different coated microspheres 1402 necessary, by allowing onecoated microspheres 1402 to detect all of the variants. At the sametime, using multiple detection regions allows for identification of theparticular variant to E. coli.

The microsphere enhanced detection system 1400 and microsphere enhanceddetection method 1500 exploit the fact that many analytes 960 havemultiple binding sites. Many microorganisms have multiple antigenepitopes or antigenic determinants where antibodies typically bind. Forexample, there are generally two such binding sites on any given speciesof antigen where a respective antibody, for example a human antibody,can bind. In embodiments, the coated microspheres 1402 bind to theanalytes 960.

In another embodiment, a staining agent 1406 is used to enhancedetection of the bound detector ligands 480. In embodiments, thestaining agent 1406 are used in combination with the coated microspheres1402 or in place of the coated microspheres 1402. There are many formsof simple staining techniques that add molecular density to the analyte960 or bound detector ligand 480 and increase the absorption of thesource radiation 204 from a radiation emitter 202 of the disk system 200that scans 1512 the biosensor disk 110. The staining agent 1406therefore enhances detection of analyte 960. Staining techniques aretraditionally split along the lines of In vivo vs. In vitro. Inembodiments, the detection substrate 120 is made of a durable substance,for example nitrogen doped SiO2, allowing the detection substrate towithstand the drying techniques of In Vitro methods. There both In vivoand In vitro techniques can be utilized. Generally, most stains willuptake to a moderate degree regardless of a cell's, or analyte's 960,state.

Gram-staining is effective at some levels due to the shared compositionsof bacterial cell walls. A basic, but effective, method uses crystalviolet to stain cell walls, iodine as a mordant (which sets the stain),and a fuchsin or safranin counterstain to mark remaining bacteria nototherwise impacted by the crystal violet. This ‘Gram staining’ techniqueis common, uncomplicated and highly useful in adding density to bothGram-positive and Gram-negative bacterium. Gram-positive bacteria staindark blue or violet because their outer layer is heavier withpeptidoglycan. Gram-negative organisms will appear red or pink becauseof a higher lipid content but significantly less peptidoglycan. Ineither instance the result is that the staining agent 1406 will absorbmore source radiation 204 from a radiation emitter 202 than might anuntreated analyte 960. Some other staining agent 1406 frequently used toenhance cellular elements, proteins and suitable molecules include:Iodine (not as a mordant), Carbol fuchsin, Methylene blue, Malachitegreen, Coomassie blue, Bismarck brown (especially good with livingcells) and Osmium tetraoxide.

Both coated microspheres 1402 and staining agent 1406 are thereforeuseful for enhancing detection of the analytes 960 because they increasethe absorption of the source radiation 204 from a radiation emitter 202of the disk system 200 that scans 1512 the biosensor disk 110.

CONCLUSION

The embodiments of the invention shown in the drawing and describedabove are exemplary of numerous embodiments that may be made within thescope of the appended claims. It is contemplated that numerous otherconfigurations of an electromagnetic biosensor system, device, andmethod and process for detecting analytes may be created takingadvantage of the disclosed approach. It is the applicant's intentionthat the scope of the patent issuing herefrom will be limited only bythe scope of the appended claims.

What is claimed is:
 1. A system for detecting one or more analytes in asample using a biosensor, comprising: a biosensor disk, with an outersurface and a layer encoded with a data path capable of being read by anelectromagnetic radiation incident upon said layer, said data pathencoded with a baseline data that is static; a detector chamber disposedalong said data path, said detector chamber having a surface foraffixing detector ligands, said surface distinct from said layer encodedwith said data path; a detector ligand for binding with an analyte, saiddetector ligand affixed to said surface for affixing detector ligands ofsaid detector chamber; a detection enhancement means for binding to saidanalyte, wherein said detection enhancement means causes a detectablechange to said electromagnetic radiation; and a disk system adapted toaccept and rotate said biosensor disk, comprising a source of saidelectromagnetic radiation focused on said layer encoded with said datapath of said biosensor disk, and a sensor adapted to detect saidelectromagnetic radiation returned from said layer encoded with saiddata path of said biosensor disk and convert said electromagneticradiation into an electrical signal.
 2. The system of claim 1, whereinsaid data path is encoded with a baseline data to provide a continuousdiscriminating signal, and said detector chamber is disposed on saiddata path such that said detection enhancement means, when bound to saidanalyte, changes said electromagnetic radiation returned from saidbiosensor disk such that a detectable signal change occurs in saidelectronic signal compared to said electronic signal produced by saidbaseline data.
 3. The system of claim 1, further comprising: a thresholdcircuit to quantize said electrical signal into a binary representationof said electrical signal; and a digital circuit to construct a digitalword from said binary representation and further comprising a CIRCencoder, a first error correction stage, and a second error correctionstage that construct a decoded frame from multiple said digital wordsand outputs errors from said first error correction stage and saidsecond error correction stage.
 4. The system of claim 3, wherein saiddetector chamber is disposed on said data path such that said detectionenhancement means, when bound to said analyte, changes saidelectromagnetic radiation returned from said biosensor disk such that adetectable signal change occurs in said electronic signal compared tosaid electronic signal produced by said baseline data, and saiddetectable signal change is selected from the group consisting of: anincrease in said output errors from said first correction stage, anincrease in said output errors from said second correction stage, anincrease in said output errors from said first correction stage and saidsecond correction stage, a change in said information of said decodedframe, and an unrecoverable error that results in said decoded framebeing improperly reconstructed.
 5. The system of claim 1, wherein saiddetector chamber is disposed on said outer surface of said biosensordisk and said detector chamber is orientated between said source ofelectromagnetic radiation and said data path.
 6. The system of claim 1,wherein said detector chamber is disposed on a separate detectorsubstrate fabricated from a material selected from the group consistingof a polymer, a silicon substrate, a doped silicon substrate, andsubstrate adapted to have an index of refraction approximately the sameas said biosensor disk, and wherein said detector chamber furthercomprises a mating feature adapted to interlock with a correspondingfeature on said biosensor disk to align said detector substrate withsaid data path.
 7. The system of claim 1, wherein said detectionenhancement means is selected from the group consisting of abiotinylated microsphere, a Streptavidin-coated microsphere, amicrosphere having a diameter between approximately 1 μm and 10 μm, apolystyrene microsphere, a latex microsphere, a biotinylated microspherethat has been immersed in a solution comprising detector ligands, aStreptavidin-coated microsphere that has been immersed in a solutioncomprising detector ligands, a microsphere having a detector ligand, anda staining agent.
 8. The system of claim 1, wherein said detectionenhancement means comprises a staining agent selected from the groupconsisting of crystal violet, iodine, carbol fuchsin, methylene blue,malachite green, coomassie blue, bismarck brown, osmium tetraoxide,fuchsin, and safranin counterstain.
 9. The system of claim 1, whereinsaid detector ligands are attached to said detector chamber using amicropatterning technique selected from the group consisting ofphotochemical micropatterning, micro-contact printing, micro-fluidnetwork urging of detector ligands in a pattern, spotting detectorligands onto said detector chamber, and spraying detector ligands ontosaid detector chamber.
 10. The system of claim 1, wherein said detectorligand is selected from the group consisting of a streptavidin receptor,an avidin-biotin receptor, a peptide, an olglionucleotide, cDNA, and achelating agent.
 11. A system for detecting one or more analytes in asample using a biosensor, comprising: a biosensor disk, furthercomprising: an outer surface; a layer encoded with a data path encodedwith a baseline data that is static and capable of being read by anelectromagnetic radiation incident upon said layer; and an interlockingfeature for accepting a detector substrate and aligning said detectorsubstrate with said data path; a detector substrate having a matingfeature for interlocking with said biosensor disk; a detector ligandadapted to bind with an analyte, said detector ligand affixed to saiddetector substrate; a coated microsphere adapted to bind with saidanalyte, wherein said coated microsphere bound to said analyte causes adetectable change to said electromagnetic radiation; and a disk systemadapted to accept and rotate said biosensor disk, comprising a source ofsaid electromagnetic radiation directed toward said layer encoded withsaid data path, and a sensor adapted to detect said electromagneticradiation returned from said data path and convert said electromagneticradiation into an electrical signal.
 12. The system of claim 11, whereinsaid coated microsphere is selected from the group consisting of abiotinylated microsphere, a Streptavidin-coated microsphere, amicrosphere having a diameter between approximately 1 μm and 10 μm, apolystyrene microsphere, a latex microsphere, a biotinylated microspherethat has been immersed in a solution comprising detector ligands, aStreptavidin-coated microsphere that has been immersed in a solutioncomprising detector ligands, and a microsphere having a detector ligand.13. The system of claim 11, wherein said detector ligand is selectedfrom the group consisting of an streptavidin receptor, an avidin-biotinreceptor, a peptide, an olglionucleotide, cDNA, and a chelating agent.14. The system of claim 11, wherein said detector substrate isfabricated from a material selected from the group consisting of: apolymer substrate, a silicon substrate, a doped silicon substrate, andsubstrate adapted to have an index of refraction approximately the sameas said biosensor disk.
 15. The system of claim 11, wherein saiddetector substrate further comprises multiple zones of detector ligands,each zone having detector ligands adapted to bind with at least oneanalyte, and wherein said microsphere is coated with a plurality ofdetector ligands associated with at least two zones.
 16. The system ofclaim 11, further comprising a staining agent applied to said detectorsubstrate to enhance detection of analytes by said disk system.
 17. Amethod for detecting an analyte in a sample, comprising: (a) introducingthe sample onto a detector substrate of a biosensor disk, wherein saidbiosensor disk is comprised of a layer having a data path encoded with abaseline data that is static, a detector chamber disposed along saiddata path, said detector chamber having a surface for affixing detectorligands that is distinct from said layer encoded with said data path,and a detector substrate adapted to interconnect with said detectorchamber, said detector substrate further comprising a detector ligandadapted to bind with the analyte, said detector ligand affixed to saidsurface for affixing detector ligands of said detector chamber; (b)binding the analyte to said detector ligand disposed on said detectorsubstrate to create a bound detector ligand; (c) introducing a coatedmicrosphere onto said detector substrate; (d) binding said coatedmicrosphere to said bound detector ligand, whereby said coatedmicrosphere creates a detectable change to an electromagnetic radiationincident upon said coated microsphere; (e) interconnecting said detectorsubstrate to said detector chamber of said biosensor disk; (f) placingsaid biosensor disk in a disk system; (g) rotating said biosensor diskwith said disk system; (h) emitting said electromagnetic radiation fromsaid disk system focused on said layer encoded with said data path onsaid biosensor disk; (i) receiving a returned electromagnetic radiationfrom said layer encoded with said data path of said biosensor disk; and(j) interpreting a change in said returned electromagnetic radiationcaused by said detectable change to indicate the presence of theanalyte.
 18. The method of claim 17, wherein said coated microsphere iscoated with a detector ligand adapted to bind with said analyte.
 19. Themethod of claim 17, wherein said (c) introducing said coated microsphereis accomplished by introducing a solution containing a plurality ofcoated microspheres onto said detector substrate.
 20. The method ofclaim 17, wherein said operations (c) and (d) are: (c) introducing astaining agent onto said bound detector ligand; and (d) binding saidstaining agent to said bound detector ligand, whereby said stainingagent and said bound detector ligand create a detectable change to anelectromagnetic radiation incident upon said coated microsphere.